无法使用 Camera2 启用 Flash Api
Can't enable Flash with the Camera2 Api
我想在我的相机应用程序中启用闪光灯 on/off，但它不起作用，
代码如下：
FlashActivity.java
public class FlashActivity extends AppCompatActivity {
private CameraManager mCameraManager;
private String mCameraId;
private Button mTorchOnOffButton;
private Boolean isTorchOn;
private TextureView textureView;
SeekBar sb;
TextToSpeech t1;
private String cameraId;
private CameraDevice cameraDevice;
private CameraCaptureSession cameraCaptureSessions;
private CaptureRequest.Builder captureRequestBuilder;
private Size imageDimension;
Bitmap src;
private static final int REQUEST_CAMERA_PERMISSION = 200;
private Handler mBackgroundHandler;
private HandlerThread mBackgroundThread;
CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback()
{
@Override
public void onOpened(@NonNull CameraDevice camera) {
cameraDevice = camera;
createCameraPreview();
}
@Override
public void onDisconnected(@NonNull CameraDevice cameraDevice) {
cameraDevice.close();
}
@Override
public void onError(@NonNull CameraDevice cameraDevice, int i) {
cameraDevice.close();
cameraDevice=null;
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d("FlashActivity", "onCreate()");
setContentView(R.layout.activity_flash);
sb = (SeekBar) findViewById(R.id.seekBar2);
textureView = (TextureView) findViewById(R.id.textureView);
mTorchOnOffButton = (Button) findViewById(R.id.button_on_off);
isTorchOn = false;
textureView.setSurfaceTextureListener(textureListener);
t1 = new TextToSpeech(getApplicationContext(), new TextToSpeech.OnInitListener() {
@Override
public void onInit(int status) {
if (status != TextToSpeech.ERROR) {
t1.setLanguage(Locale.UK);
}
}
});
ToggleButton toggle = (ToggleButton) findViewById(R.id.toggleButton);
toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (isChecked) {
freeze();
String toSpeak = "Camera Freeze";
Toast.makeText(getApplicationContext(), toSpeak, Toast.LENGTH_SHORT).show();
t1.speak(toSpeak, TextToSpeech.QUEUE_FLUSH, null);
} else {
updatePreview();
String toSpeak = "Back to Live Camera";
Toast.makeText(getApplicationContext(), toSpeak, Toast.LENGTH_SHORT).show();
t1.speak(toSpeak, TextToSpeech.QUEUE_FLUSH, null);
}
}
});
Boolean isFlashAvailable = getApplicationContext().getPackageManager()
.hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
if (!isFlashAvailable) {
AlertDialog alert = new AlertDialog.Builder(FlashActivity.this)
.create();
alert.setTitle("Error !!");
alert.setMessage("Your device doesn't support flash light!");
alert.setButton(DialogInterface.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// closing the application
finish();
System.exit(0);
}
});
alert.show();
return;
}
mCameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
try {
mCameraId = mCameraManager.getCameraIdList()[0];
} catch (CameraAccessException e) {
e.printStackTrace();
}
mTorchOnOffButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
if (isTorchOn) {
turnOffFlashLight();
isTorchOn = false;
} else {
turnOnFlashLight();
isTorchOn = true;
}
} catch (Exception e) {
e.printStackTrace();
}
}
});
sb.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
float scale = ((progress / 10.0f) + 1);
textureView.setScaleX(scale);
textureView.setScaleY(scale);
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
}
public void turnOnFlashLight() {
try {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
mCameraManager.setTorchMode(mCameraId, true);
}
} catch (Exception e) {
e.printStackTrace();
}
}
public void turnOffFlashLight() {
try {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
mCameraManager.setTorchMode(mCameraId, false);
}
} catch (Exception e) {
e.printStackTrace();
}
}
ArrayList rev;
public void freeze() {
Thread td = new Thread(new Runnable() {
public void run() {
Bitmap bmp = textureView.getBitmap();
rev = new ArrayList<Bitmap>();
rev.add(bmp);
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(), "" + rev.size(), Toast.LENGTH_LONG).show();
try {
cameraCaptureSessions.stopRepeating();
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
});
}
});
td.start();
}
private void createCameraPreview() {
try {
SurfaceTexture texture = textureView.getSurfaceTexture();
assert texture != null;
texture.setDefaultBufferSize(imageDimension.getWidth(), imageDimension.getHeight());
Surface surface = new Surface(texture);
captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
captureRequestBuilder.addTarget(surface);
cameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
if (cameraDevice == null)
return;
cameraCaptureSessions = cameraCaptureSession;
updatePreview();
}
@Override
public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
Toast.makeText(FlashActivity.this, "Changed", Toast.LENGTH_SHORT).show();
}
}, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private void updatePreview() {
if (cameraDevice == null)
Toast.makeText(this, "Error", Toast.LENGTH_SHORT).show();
captureRequestBuilder.set(CaptureRequest.CONTROL_MODE, CaptureRequest.CONTROL_MODE_AUTO);
try {
cameraCaptureSessions.setRepeatingRequest(captureRequestBuilder.build(), null, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private void openCamera() {
CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
try {
cameraId = manager.getCameraIdList()[0];
CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
assert map != null;
imageDimension = map.getOutputSizes(SurfaceTexture.class)[0];
//Check realtime permission if run higher API 23
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{
Manifest.permission.CAMERA,
Manifest.permission.WRITE_EXTERNAL_STORAGE
}, REQUEST_CAMERA_PERMISSION);
return;
}
manager.openCamera(cameraId, stateCallback, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
TextureView.SurfaceTextureListener textureListener = new TextureView.SurfaceTextureListener() {
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int i, int i1) {
openCamera();
}
@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int i, int i1) {
}
@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
return false;
}
@Override
public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {
}
};
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if(requestCode == REQUEST_CAMERA_PERMISSION)
{
if(grantResults[0] != PackageManager.PERMISSION_GRANTED)
{
Toast.makeText(this, "You can't use camera without permission", Toast.LENGTH_SHORT).show();
finish();
}
}
}
@Override
protected void onStop() {
super.onStop();
if(isTorchOn){
turnOffFlashLight();
}
}
@Override
protected void onPause() {
super.onPause();
if(isTorchOn){
turnOffFlashLight();
}
}
@Override
protected void onResume() {
super.onResume();
if(isTorchOn){
turnOnFlashLight();
}
}
}
这是我在 LOG
得到的
04-03 16:38:34.948 10905-10905/com.example.sumesh.myapplication W/System.err: android.hardware.camera2.CameraAccessException: The camera device is in use already
at android.hardware.camera2.utils.CameraBinderDecorator.throwOnError(CameraBinderDecorator.java:123)
at android.hardware.camera2.utils.CameraBinderDecorator$CameraBinderDecoratorListener.onAfterInvocation(CameraBinderDecorator.java:73)
at android.hardware.camera2.utils.Decorator.invoke(Decorator.java:81)
at java.lang.reflect.Proxy.invoke(Proxy.java:393)
at $Proxy0.setTorchMode(Unknown Source)
at android.hardware.camera2.CameraManager$CameraManagerGlobal.setTorchMode(CameraManager.java:884)
at android.hardware.camera2.CameraManager.setTorchMode(CameraManager.java:501)
at com.example.sumesh.myapplication.FlashActivity.turnOffFlashLight(FlashActivity.java:204)
at com.example.sumesh.myapplication.FlashActivity.onClick(FlashActivity.java:150)
at android.view.View.performClick(View.java:5215)
at android.view.View$PerformClick.run(View.java:21196)
}
我使用了线性布局而不是 relativeIlayout，但是我
我无法弄清楚到底是什么东西造成了错误，
所有权限都已在 android 清单中定义，
有什么建议吗？
试试这个，使用 camera2 拍照的完整代码 API，Fragment_Camera4
/**
* A simple {@link Fragment} subclass.
*/
public class Fragment_Camera4 extends Fragment implements
AspectRatioFragment.Listener {
private View view;
private static final String TAG = "MainActivity";
private static final int REQUEST_CAMERA_PERMISSION = 1;
private static final String FRAGMENT_DIALOG = "dialog";
private static final int[] FLASH_OPTIONS = {
CameraView.FLASH_OFF,
CameraView.FLASH_ON,
};
private static final int[] FLASH_ICONS = {
R.drawable.ic_flash_off,
R.drawable.ic_flash_on,
};
private static final int[] FLASH_TITLES = {
R.string.flash_auto,
R.string.flash_off,
R.string.flash_on,
};
private int mCurrentFlash;
private CameraView mCameraView;
private Handler mBackgroundHandler;
private View.OnClickListener mOnClickListener = new View.OnClickListener() {
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.take_picture:
if (mCameraView != null) {
mCameraView.takePicture();
}
break;
case R.id.btn_switch_camera:
if (mCameraView != null) {
int facing = mCameraView.getFacing();
mCameraView.setFacing(facing == CameraView.FACING_FRONT ?
CameraView.FACING_BACK : CameraView.FACING_FRONT);
if (facing == CameraView.FACING_FRONT) {
btn_flash_onOff.setVisibility(View.VISIBLE);
} else {
btn_flash_onOff.setVisibility(View.GONE);
}
}
break;
case R.id.btn_flash_onOff:
if (mCameraView != null) {
mCurrentFlash = (mCurrentFlash + 1) % FLASH_OPTIONS.length;
btn_flash_onOff.setImageResource(FLASH_ICONS[mCurrentFlash]);
mCameraView.setFlash(FLASH_OPTIONS[mCurrentFlash]);
}
break;
}
}
};
ImageButton btn_flash_onOff;
public Fragment_Camera4() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
view = inflater.inflate(R.layout.fragment_fragment__camera4, container, false);
mCameraView = (CameraView) view.findViewById(R.id.camera);
if (mCameraView != null) {
mCameraView.addCallback(mCallback);
}
ImageButton fab = (ImageButton) view.findViewById(R.id.take_picture);
ImageButton btn_switch_camera = (ImageButton) view.findViewById(R.id.btn_switch_camera);
btn_flash_onOff = (ImageButton) view.findViewById(R.id.btn_flash_onOff);
if (fab != null) {
fab.setOnClickListener(mOnClickListener);
btn_switch_camera.setOnClickListener(mOnClickListener);
btn_flash_onOff.setOnClickListener(mOnClickListener);
}
return view;
}
@Override
public void onResume() {
super.onResume();
mCameraView.start();
}
@Override
public void onPause() {
mCameraView.stop();
super.onPause();
}
@Override
public void onDestroy() {
super.onDestroy();
if (mBackgroundHandler != null) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
mBackgroundHandler.getLooper().quitSafely();
} else {
mBackgroundHandler.getLooper().quit();
}
mBackgroundHandler = null;
}
}
@Override
public void onAspectRatioSelected(@NonNull AspectRatio ratio) {
if (mCameraView != null) {
Toast.makeText(getActivity(), ratio.toString(), Toast.LENGTH_SHORT).show();
mCameraView.setAspectRatio(ratio);
}
}
private Handler getBackgroundHandler() {
if (mBackgroundHandler == null) {
HandlerThread thread = new HandlerThread("background");
thread.start();
mBackgroundHandler = new Handler(thread.getLooper());
}
return mBackgroundHandler;
}
private CameraView.Callback mCallback
= new CameraView.Callback() {
@Override
public void onCameraOpened(CameraView cameraView) {
Log.d(TAG, "onCameraOpened");
}
@Override
public void onCameraClosed(CameraView cameraView) {
Log.d(TAG, "onCameraClosed");
}
@Override
public void onPictureTaken(CameraView cameraView, final byte[] data) {
Log.d(TAG, "onPictureTaken " + data.length);
Toast.makeText(cameraView.getContext(), R.string.picture_taken, Toast.LENGTH_SHORT)
.show();
getBackgroundHandler().post(new Runnable() {
@Override
public void run() {
String root = Environment.getExternalStorageDirectory().toString();
File myDir = new File(root + "/_saved_images");
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image-" + n + ".jpg";
File file = new File(myDir, fname);
String final_path = myDir + "/" + fname;
OutputStream os = null;
try {
os = new FileOutputStream(file);
os.write(data);
os.close();
} catch (IOException e) {
Log.w(TAG, "Cannot write to " + file, e);
} finally {
if (os != null) {
try {
os.close();
} catch (IOException e) {
// Ignore
}
}
}
Bundle bundle = new Bundle();
bundle.putString("path", final_path);
bundle.putString("type", "picture");
Fragment_Post_Image_Detail post_image_detail = new Fragment_Post_Image_Detail();
post_image_detail.setArguments(bundle);
((BaseActivity) getActivity()).replaceFragmentWithBackstack(post_image_detail);
}
});
}
};
}
然后Cameraviewclass
导入 android.content.res.TypedArray；
导入 android.os.Build；
导入 android.os.Parcel；
导入 android.os.Parcel 能够；
导入 android.support.annotation.IntDef；
导入 android.support.annotation.NonNull；
导入 android.support.annotation.Nullable；
导入 android.support.v4.os.ParcelableCompat;
导入 android.support.v4.os.ParcelableCompatCreatorCallbacks；
导入 android.support.v4.view.ViewCompat;
导入 android.util.AttributeSet；
导入 android.widget.FrameLayout;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.ArrayList;
import java.util.Set;
public class CameraView extends FrameLayout {
/** The camera device faces the opposite direction as the device's screen. */
public static final int FACING_BACK = Constants.FACING_BACK;
/** The camera device faces the same direction as the device's screen. */
public static final int FACING_FRONT = Constants.FACING_FRONT;
/** Direction the camera faces relative to device screen. */
@IntDef({FACING_BACK, FACING_FRONT})
@Retention(RetentionPolicy.SOURCE)
public @interface Facing {
}
/** Flash will not be fired. */
public static final int FLASH_OFF = Constants.FLASH_OFF;
/** Flash will always be fired during snapshot. */
public static final int FLASH_ON = Constants.FLASH_ON;
/** Constant emission of light during preview, auto-focus and snapshot. */
public static final int FLASH_TORCH = Constants.FLASH_TORCH;
/** Flash will be fired automatically when required. */
public static final int FLASH_AUTO = Constants.FLASH_AUTO;
/** Flash will be fired in red-eye reduction mode. */
public static final int FLASH_RED_EYE = Constants.FLASH_RED_EYE;
/** The mode for for the camera device's flash control */
@IntDef({FLASH_OFF, FLASH_ON, FLASH_TORCH, FLASH_AUTO, FLASH_RED_EYE})
public @interface Flash {
}
CameraViewImpl mImpl;
private final CallbackBridge mCallbacks;
private boolean mAdjustViewBounds;
private final DisplayOrientationDetector mDisplayOrientationDetector;
public CameraView(Context context) {
this(context, null);
}
public CameraView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
@SuppressWarnings("WrongConstant")
public CameraView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
if (isInEditMode()){
mCallbacks = null;
mDisplayOrientationDetector = null;
return;
}
// Internal setup
final PreviewImpl preview = createPreviewImpl(context);
mCallbacks = new CallbackBridge();
if (Build.VERSION.SDK_INT < 21) {
mImpl = new Camera1(mCallbacks, preview);
} else if (Build.VERSION.SDK_INT < 23) {
mImpl = new Camera2(mCallbacks, preview, context);
} else {
mImpl = new Camera2Api23(mCallbacks, preview, context);
}
// Attributes
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CameraView, defStyleAttr,
R.style.Widget_CameraView);
mAdjustViewBounds = a.getBoolean(R.styleable.CameraView_android_adjustViewBounds, false);
setFacing(a.getInt(R.styleable.CameraView_facing, FACING_BACK));
String aspectRatio = a.getString(R.styleable.CameraView_aspectRatio);
if (aspectRatio != null) {
setAspectRatio(AspectRatio.parse(aspectRatio));
} else {
setAspectRatio(Constants.DEFAULT_ASPECT_RATIO);
}
setAutoFocus(a.getBoolean(R.styleable.CameraView_autoFocus, true));
setFlash(a.getInt(R.styleable.CameraView_flash, Constants.FLASH_AUTO));
a.recycle();
// Display orientation detector
mDisplayOrientationDetector = new DisplayOrientationDetector(context) {
@Override
public void onDisplayOrientationChanged(int displayOrientation) {
mImpl.setDisplayOrientation(displayOrientation);
}
};
}
@NonNull
private PreviewImpl createPreviewImpl(Context context) {
PreviewImpl preview;
if (Build.VERSION.SDK_INT < 14) {
preview = new SurfaceViewPreview(context, this);
} else {
preview = new TextureViewPreview(context, this);
}
return preview;
}
@Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
if (!isInEditMode()) {
mDisplayOrientationDetector.enable(ViewCompat.getDisplay(this));
}
}
@Override
protected void onDetachedFromWindow() {
if (!isInEditMode()) {
mDisplayOrientationDetector.disable();
}
super.onDetachedFromWindow();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if (isInEditMode()){
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
return;
}
// Handle android:adjustViewBounds
if (mAdjustViewBounds) {
if (!isCameraOpened()) {
mCallbacks.reserveRequestLayoutOnOpen();
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
return;
}
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
if (widthMode == MeasureSpec.EXACTLY && heightMode != MeasureSpec.EXACTLY) {
final AspectRatio ratio = getAspectRatio();
assert ratio != null;
int height = (int) (MeasureSpec.getSize(widthMeasureSpec) * ratio.toFloat());
if (heightMode == MeasureSpec.AT_MOST) {
height = Math.min(height, MeasureSpec.getSize(heightMeasureSpec));
}
super.onMeasure(widthMeasureSpec,
MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY));
} else if (widthMode != MeasureSpec.EXACTLY && heightMode == MeasureSpec.EXACTLY) {
final AspectRatio ratio = getAspectRatio();
assert ratio != null;
int width = (int) (MeasureSpec.getSize(heightMeasureSpec) * ratio.toFloat());
if (widthMode == MeasureSpec.AT_MOST) {
width = Math.min(width, MeasureSpec.getSize(widthMeasureSpec));
}
super.onMeasure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY),
heightMeasureSpec);
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
// Measure the TextureView
int width = getMeasuredWidth();
int height = getMeasuredHeight();
AspectRatio ratio = getAspectRatio();
if (mDisplayOrientationDetector.getLastKnownDisplayOrientation() % 180 == 0) {
ratio = ratio.inverse();
}
assert ratio != null;
if (height < width * ratio.getY() / ratio.getX()) {
mImpl.getView().measure(
MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(width * ratio.getY() / ratio.getX(),
MeasureSpec.EXACTLY));
} else {
mImpl.getView().measure(
MeasureSpec.makeMeasureSpec(height * ratio.getX() / ratio.getY(),
MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY));
}
}
@Override
protected Parcelable onSaveInstanceState() {
SavedState state = new SavedState(super.onSaveInstanceState());
state.facing = getFacing();
state.ratio = getAspectRatio();
state.autoFocus = getAutoFocus();
state.flash = getFlash();
return state;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (!(state instanceof SavedState)) {
super.onRestoreInstanceState(state);
return;
}
SavedState ss = (SavedState) state;
super.onRestoreInstanceState(ss.getSuperState());
setFacing(ss.facing);
setAspectRatio(ss.ratio);
setAutoFocus(ss.autoFocus);
setFlash(ss.flash);
}
/**
* Open a camera device and start showing camera preview. This is typically called from
* {@link Activity#onResume()}.
*/
public void start() {
if (!mImpl.start()) {
//store the state ,and restore this state after fall back o Camera1
Parcelable state=onSaveInstanceState();
// Camera2 uses legacy hardware layer; fall back to Camera1
mImpl = new Camera1(mCallbacks, createPreviewImpl(getContext()));
onRestoreInstanceState(state);
mImpl.start();
}
}
/**
* Stop camera preview and close the device. This is typically called from
* {@link Activity#onPause()}.
*/
public void stop() {
mImpl.stop();
}
/**
* @return {@code true} if the camera is opened.
*/
public boolean isCameraOpened() {
return mImpl.isCameraOpened();
}
/**
* Add a new callback.
*
* @param callback The {@link Callback} to add.
* @see #removeCallback(Callback)
*/
public void addCallback(@NonNull Callback callback) {
mCallbacks.add(callback);
}
/**
* Remove a callback.
*
* @param callback The {@link Callback} to remove.
* @see #addCallback(Callback)
*/
public void removeCallback(@NonNull Callback callback) {
mCallbacks.remove(callback);
}
/**
* @param adjustViewBounds {@code true} if you want the CameraView to adjust its bounds to
* preserve the aspect ratio of camera.
* @see #getAdjustViewBounds()
*/
public void setAdjustViewBounds(boolean adjustViewBounds) {
if (mAdjustViewBounds != adjustViewBounds) {
mAdjustViewBounds = adjustViewBounds;
requestLayout();
}
}
/**
* @return True when this CameraView is adjusting its bounds to preserve the aspect ratio of
* camera.
* @see #setAdjustViewBounds(boolean)
*/
public boolean getAdjustViewBounds() {
return mAdjustViewBounds;
}
/**
* Chooses camera by the direction it faces.
*
* @param facing The camera facing. Must be either {@link #FACING_BACK} or
* {@link #FACING_FRONT}.
*/
public void setFacing(@Facing int facing) {
mImpl.setFacing(facing);
}
/**
* Gets the direction that the current camera faces.
*
* @return The camera facing.
*/
@Facing
public int getFacing() {
//noinspection WrongConstant
return mImpl.getFacing();
}
/**
* Gets all the aspect ratios supported by the current camera.
*/
public Set<AspectRatio> getSupportedAspectRatios() {
return mImpl.getSupportedAspectRatios();
}
/**
* Sets the aspect ratio of camera.
*
* @param ratio The {@link AspectRatio} to be set.
*/
public void setAspectRatio(@NonNull AspectRatio ratio) {
if (mImpl.setAspectRatio(ratio)) {
requestLayout();
}
}
/**
* Gets the current aspect ratio of camera.
*
* @return The current {@link AspectRatio}. Can be {@code null} if no camera is opened yet.
*/
@Nullable
public AspectRatio getAspectRatio() {
return mImpl.getAspectRatio();
}
/**
* Enables or disables the continuous auto-focus mode. When the current camera doesn't support
* auto-focus, calling this method will be ignored.
*
* @param autoFocus {@code true} to enable continuous auto-focus mode. {@code false} to
* disable it.
*/
public void setAutoFocus(boolean autoFocus) {
mImpl.setAutoFocus(autoFocus);
}
/**
* Returns whether the continuous auto-focus mode is enabled.
*
* @return {@code true} if the continuous auto-focus mode is enabled. {@code false} if it is
* disabled, or if it is not supported by the current camera.
*/
public boolean getAutoFocus() {
return mImpl.getAutoFocus();
}
/**
* Sets the flash mode.
*
* @param flash The desired flash mode.
*/
public void setFlash(@Flash int flash) {
mImpl.setFlash(flash);
}
/**
* Gets the current flash mode.
*
* @return The current flash mode.
*/
@Flash
public int getFlash() {
//noinspection WrongConstant
return mImpl.getFlash();
}
/**
* Take a picture. The result will be returned to
* {@link Callback#onPictureTaken(CameraView, byte[])}.
*/
public void takePicture() {
mImpl.takePicture();
}
private class CallbackBridge implements CameraViewImpl.Callback {
private final ArrayList<Callback> mCallbacks = new ArrayList<>();
private boolean mRequestLayoutOnOpen;
CallbackBridge() {
}
public void add(Callback callback) {
mCallbacks.add(callback);
}
public void remove(Callback callback) {
mCallbacks.remove(callback);
}
@Override
public void onCameraOpened() {
if (mRequestLayoutOnOpen) {
mRequestLayoutOnOpen = false;
requestLayout();
}
for (Callback callback : mCallbacks) {
callback.onCameraOpened(CameraView.this);
}
}
@Override
public void onCameraClosed() {
for (Callback callback : mCallbacks) {
callback.onCameraClosed(CameraView.this);
}
}
@Override
public void onPictureTaken(byte[] data) {
for (Callback callback : mCallbacks) {
callback.onPictureTaken(CameraView.this, data);
}
}
public void reserveRequestLayoutOnOpen() {
mRequestLayoutOnOpen = true;
}
}
protected static class SavedState extends BaseSavedState {
@Facing
int facing;
AspectRatio ratio;
boolean autoFocus;
@Flash
int flash;
@SuppressWarnings("WrongConstant")
public SavedState(Parcel source, ClassLoader loader) {
super(source);
facing = source.readInt();
ratio = source.readParcelable(loader);
autoFocus = source.readByte() != 0;
flash = source.readInt();
}
public SavedState(Parcelable superState) {
super(superState);
}
@Override
public void writeToParcel(Parcel out, int flags) {
super.writeToParcel(out, flags);
out.writeInt(facing);
out.writeParcelable(ratio, 0);
out.writeByte((byte) (autoFocus ? 1 : 0));
out.writeInt(flash);
}
public static final Parcelable.Creator<SavedState> CREATOR
= ParcelableCompat.newCreator(new ParcelableCompatCreatorCallbacks<SavedState>() {
@Override
public SavedState createFromParcel(Parcel in, ClassLoader loader) {
return new SavedState(in, loader);
}
@Override
public SavedState[] newArray(int size) {
return new SavedState[size];
}
});
}
/**
* Callback for monitoring events about {@link CameraView}.
*/
@SuppressWarnings("UnusedParameters")
public abstract static class Callback {
/**
* Called when camera is opened.
*
* @param cameraView The associated {@link CameraView}.
*/
public void onCameraOpened(CameraView cameraView) {
}
/**
* Called when camera is closed.
*
* @param cameraView The associated {@link CameraView}.
*/
public void onCameraClosed(CameraView cameraView) {
}
/**
* Called when a picture is taken.
*
* @param cameraView The associated {@link CameraView}.
* @param data JPEG data.
*/
public void onPictureTaken(CameraView cameraView, byte[] data) {
}
}
}
和xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/colorgrey">
<com.google.android.cameraview.CameraView
android:id="@+id/camera"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:adjustViewBounds="true"
android:background="@android:color/black" />
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true" />
<ImageButton
android:id="@+id/take_picture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="20dp"
android:background="#0000"
app:srcCompat="@drawable/ic_take_pic" />
<ImageButton
android:id="@+id/btn_switch_camera"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_margin="20dp"
android:background="#0000"
app:srcCompat="@drawable/ic_reset_camera" />
<ImageButton
android:id="@+id/btn_flash_onOff"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_margin="20dp"
android:background="#0000"
app:srcCompat="@drawable/ic_flash_off" />
</RelativeLayout>
另外不要忘记在 OnCreate() 中添加运行时权限
我想在我的相机应用程序中启用闪光灯 on/off，但它不起作用，
代码如下：
FlashActivity.java
public class FlashActivity extends AppCompatActivity {
private CameraManager mCameraManager;
private String mCameraId;
private Button mTorchOnOffButton;
private Boolean isTorchOn;
private TextureView textureView;
SeekBar sb;
TextToSpeech t1;
private String cameraId;
private CameraDevice cameraDevice;
private CameraCaptureSession cameraCaptureSessions;
private CaptureRequest.Builder captureRequestBuilder;
private Size imageDimension;
Bitmap src;
private static final int REQUEST_CAMERA_PERMISSION = 200;
private Handler mBackgroundHandler;
private HandlerThread mBackgroundThread;
CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback()
{
@Override
public void onOpened(@NonNull CameraDevice camera) {
cameraDevice = camera;
createCameraPreview();
}
@Override
public void onDisconnected(@NonNull CameraDevice cameraDevice) {
cameraDevice.close();
}
@Override
public void onError(@NonNull CameraDevice cameraDevice, int i) {
cameraDevice.close();
cameraDevice=null;
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d("FlashActivity", "onCreate()");
setContentView(R.layout.activity_flash);
sb = (SeekBar) findViewById(R.id.seekBar2);
textureView = (TextureView) findViewById(R.id.textureView);
mTorchOnOffButton = (Button) findViewById(R.id.button_on_off);
isTorchOn = false;
textureView.setSurfaceTextureListener(textureListener);
t1 = new TextToSpeech(getApplicationContext(), new TextToSpeech.OnInitListener() {
@Override
public void onInit(int status) {
if (status != TextToSpeech.ERROR) {
t1.setLanguage(Locale.UK);
}
}
});
ToggleButton toggle = (ToggleButton) findViewById(R.id.toggleButton);
toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (isChecked) {
freeze();
String toSpeak = "Camera Freeze";
Toast.makeText(getApplicationContext(), toSpeak, Toast.LENGTH_SHORT).show();
t1.speak(toSpeak, TextToSpeech.QUEUE_FLUSH, null);
} else {
updatePreview();
String toSpeak = "Back to Live Camera";
Toast.makeText(getApplicationContext(), toSpeak, Toast.LENGTH_SHORT).show();
t1.speak(toSpeak, TextToSpeech.QUEUE_FLUSH, null);
}
}
});
Boolean isFlashAvailable = getApplicationContext().getPackageManager()
.hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
if (!isFlashAvailable) {
AlertDialog alert = new AlertDialog.Builder(FlashActivity.this)
.create();
alert.setTitle("Error !!");
alert.setMessage("Your device doesn't support flash light!");
alert.setButton(DialogInterface.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// closing the application
finish();
System.exit(0);
}
});
alert.show();
return;
}
mCameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
try {
mCameraId = mCameraManager.getCameraIdList()[0];
} catch (CameraAccessException e) {
e.printStackTrace();
}
mTorchOnOffButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
if (isTorchOn) {
turnOffFlashLight();
isTorchOn = false;
} else {
turnOnFlashLight();
isTorchOn = true;
}
} catch (Exception e) {
e.printStackTrace();
}
}
});
sb.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
float scale = ((progress / 10.0f) + 1);
textureView.setScaleX(scale);
textureView.setScaleY(scale);
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
}
public void turnOnFlashLight() {
try {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
mCameraManager.setTorchMode(mCameraId, true);
}
} catch (Exception e) {
e.printStackTrace();
}
}
public void turnOffFlashLight() {
try {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
mCameraManager.setTorchMode(mCameraId, false);
}
} catch (Exception e) {
e.printStackTrace();
}
}
ArrayList rev;
public void freeze() {
Thread td = new Thread(new Runnable() {
public void run() {
Bitmap bmp = textureView.getBitmap();
rev = new ArrayList<Bitmap>();
rev.add(bmp);
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(), "" + rev.size(), Toast.LENGTH_LONG).show();
try {
cameraCaptureSessions.stopRepeating();
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
});
}
});
td.start();
}
private void createCameraPreview() {
try {
SurfaceTexture texture = textureView.getSurfaceTexture();
assert texture != null;
texture.setDefaultBufferSize(imageDimension.getWidth(), imageDimension.getHeight());
Surface surface = new Surface(texture);
captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
captureRequestBuilder.addTarget(surface);
cameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
if (cameraDevice == null)
return;
cameraCaptureSessions = cameraCaptureSession;
updatePreview();
}
@Override
public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
Toast.makeText(FlashActivity.this, "Changed", Toast.LENGTH_SHORT).show();
}
}, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private void updatePreview() {
if (cameraDevice == null)
Toast.makeText(this, "Error", Toast.LENGTH_SHORT).show();
captureRequestBuilder.set(CaptureRequest.CONTROL_MODE, CaptureRequest.CONTROL_MODE_AUTO);
try {
cameraCaptureSessions.setRepeatingRequest(captureRequestBuilder.build(), null, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private void openCamera() {
CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
try {
cameraId = manager.getCameraIdList()[0];
CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
assert map != null;
imageDimension = map.getOutputSizes(SurfaceTexture.class)[0];
//Check realtime permission if run higher API 23
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{
Manifest.permission.CAMERA,
Manifest.permission.WRITE_EXTERNAL_STORAGE
}, REQUEST_CAMERA_PERMISSION);
return;
}
manager.openCamera(cameraId, stateCallback, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
TextureView.SurfaceTextureListener textureListener = new TextureView.SurfaceTextureListener() {
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int i, int i1) {
openCamera();
}
@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int i, int i1) {
}
@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
return false;
}
@Override
public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {
}
};
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if(requestCode == REQUEST_CAMERA_PERMISSION)
{
if(grantResults[0] != PackageManager.PERMISSION_GRANTED)
{
Toast.makeText(this, "You can't use camera without permission", Toast.LENGTH_SHORT).show();
finish();
}
}
}
@Override
protected void onStop() {
super.onStop();
if(isTorchOn){
turnOffFlashLight();
}
}
@Override
protected void onPause() {
super.onPause();
if(isTorchOn){
turnOffFlashLight();
}
}
@Override
protected void onResume() {
super.onResume();
if(isTorchOn){
turnOnFlashLight();
}
}
}
这是我在 LOG
得到的04-03 16:38:34.948 10905-10905/com.example.sumesh.myapplication W/System.err: android.hardware.camera2.CameraAccessException: The camera device is in use already
at android.hardware.camera2.utils.CameraBinderDecorator.throwOnError(CameraBinderDecorator.java:123)
at android.hardware.camera2.utils.CameraBinderDecorator$CameraBinderDecoratorListener.onAfterInvocation(CameraBinderDecorator.java:73)
at android.hardware.camera2.utils.Decorator.invoke(Decorator.java:81)
at java.lang.reflect.Proxy.invoke(Proxy.java:393)
at $Proxy0.setTorchMode(Unknown Source)
at android.hardware.camera2.CameraManager$CameraManagerGlobal.setTorchMode(CameraManager.java:884)
at android.hardware.camera2.CameraManager.setTorchMode(CameraManager.java:501)
at com.example.sumesh.myapplication.FlashActivity.turnOffFlashLight(FlashActivity.java:204)
at com.example.sumesh.myapplication.FlashActivity.onClick(FlashActivity.java:150)
at android.view.View.performClick(View.java:5215)
at android.view.View$PerformClick.run(View.java:21196)
}
我使用了线性布局而不是 relativeIlayout，但是我
我无法弄清楚到底是什么东西造成了错误，
所有权限都已在 android 清单中定义，
有什么建议吗？
试试这个，使用 camera2 拍照的完整代码 API，Fragment_Camera4
/**
* A simple {@link Fragment} subclass.
*/
public class Fragment_Camera4 extends Fragment implements
AspectRatioFragment.Listener {
private View view;
private static final String TAG = "MainActivity";
private static final int REQUEST_CAMERA_PERMISSION = 1;
private static final String FRAGMENT_DIALOG = "dialog";
private static final int[] FLASH_OPTIONS = {
CameraView.FLASH_OFF,
CameraView.FLASH_ON,
};
private static final int[] FLASH_ICONS = {
R.drawable.ic_flash_off,
R.drawable.ic_flash_on,
};
private static final int[] FLASH_TITLES = {
R.string.flash_auto,
R.string.flash_off,
R.string.flash_on,
};
private int mCurrentFlash;
private CameraView mCameraView;
private Handler mBackgroundHandler;
private View.OnClickListener mOnClickListener = new View.OnClickListener() {
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.take_picture:
if (mCameraView != null) {
mCameraView.takePicture();
}
break;
case R.id.btn_switch_camera:
if (mCameraView != null) {
int facing = mCameraView.getFacing();
mCameraView.setFacing(facing == CameraView.FACING_FRONT ?
CameraView.FACING_BACK : CameraView.FACING_FRONT);
if (facing == CameraView.FACING_FRONT) {
btn_flash_onOff.setVisibility(View.VISIBLE);
} else {
btn_flash_onOff.setVisibility(View.GONE);
}
}
break;
case R.id.btn_flash_onOff:
if (mCameraView != null) {
mCurrentFlash = (mCurrentFlash + 1) % FLASH_OPTIONS.length;
btn_flash_onOff.setImageResource(FLASH_ICONS[mCurrentFlash]);
mCameraView.setFlash(FLASH_OPTIONS[mCurrentFlash]);
}
break;
}
}
};
ImageButton btn_flash_onOff;
public Fragment_Camera4() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
view = inflater.inflate(R.layout.fragment_fragment__camera4, container, false);
mCameraView = (CameraView) view.findViewById(R.id.camera);
if (mCameraView != null) {
mCameraView.addCallback(mCallback);
}
ImageButton fab = (ImageButton) view.findViewById(R.id.take_picture);
ImageButton btn_switch_camera = (ImageButton) view.findViewById(R.id.btn_switch_camera);
btn_flash_onOff = (ImageButton) view.findViewById(R.id.btn_flash_onOff);
if (fab != null) {
fab.setOnClickListener(mOnClickListener);
btn_switch_camera.setOnClickListener(mOnClickListener);
btn_flash_onOff.setOnClickListener(mOnClickListener);
}
return view;
}
@Override
public void onResume() {
super.onResume();
mCameraView.start();
}
@Override
public void onPause() {
mCameraView.stop();
super.onPause();
}
@Override
public void onDestroy() {
super.onDestroy();
if (mBackgroundHandler != null) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
mBackgroundHandler.getLooper().quitSafely();
} else {
mBackgroundHandler.getLooper().quit();
}
mBackgroundHandler = null;
}
}
@Override
public void onAspectRatioSelected(@NonNull AspectRatio ratio) {
if (mCameraView != null) {
Toast.makeText(getActivity(), ratio.toString(), Toast.LENGTH_SHORT).show();
mCameraView.setAspectRatio(ratio);
}
}
private Handler getBackgroundHandler() {
if (mBackgroundHandler == null) {
HandlerThread thread = new HandlerThread("background");
thread.start();
mBackgroundHandler = new Handler(thread.getLooper());
}
return mBackgroundHandler;
}
private CameraView.Callback mCallback
= new CameraView.Callback() {
@Override
public void onCameraOpened(CameraView cameraView) {
Log.d(TAG, "onCameraOpened");
}
@Override
public void onCameraClosed(CameraView cameraView) {
Log.d(TAG, "onCameraClosed");
}
@Override
public void onPictureTaken(CameraView cameraView, final byte[] data) {
Log.d(TAG, "onPictureTaken " + data.length);
Toast.makeText(cameraView.getContext(), R.string.picture_taken, Toast.LENGTH_SHORT)
.show();
getBackgroundHandler().post(new Runnable() {
@Override
public void run() {
String root = Environment.getExternalStorageDirectory().toString();
File myDir = new File(root + "/_saved_images");
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image-" + n + ".jpg";
File file = new File(myDir, fname);
String final_path = myDir + "/" + fname;
OutputStream os = null;
try {
os = new FileOutputStream(file);
os.write(data);
os.close();
} catch (IOException e) {
Log.w(TAG, "Cannot write to " + file, e);
} finally {
if (os != null) {
try {
os.close();
} catch (IOException e) {
// Ignore
}
}
}
Bundle bundle = new Bundle();
bundle.putString("path", final_path);
bundle.putString("type", "picture");
Fragment_Post_Image_Detail post_image_detail = new Fragment_Post_Image_Detail();
post_image_detail.setArguments(bundle);
((BaseActivity) getActivity()).replaceFragmentWithBackstack(post_image_detail);
}
});
}
};
}
然后Cameraviewclass
导入 android.content.res.TypedArray；
导入 android.os.Build；
导入 android.os.Parcel；
导入 android.os.Parcel 能够；
导入 android.support.annotation.IntDef；
导入 android.support.annotation.NonNull；
导入 android.support.annotation.Nullable；
导入 android.support.v4.os.ParcelableCompat;
导入 android.support.v4.os.ParcelableCompatCreatorCallbacks；
导入 android.support.v4.view.ViewCompat;
导入 android.util.AttributeSet；
导入 android.widget.FrameLayout;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.ArrayList;
import java.util.Set;
public class CameraView extends FrameLayout {
/** The camera device faces the opposite direction as the device's screen. */
public static final int FACING_BACK = Constants.FACING_BACK;
/** The camera device faces the same direction as the device's screen. */
public static final int FACING_FRONT = Constants.FACING_FRONT;
/** Direction the camera faces relative to device screen. */
@IntDef({FACING_BACK, FACING_FRONT})
@Retention(RetentionPolicy.SOURCE)
public @interface Facing {
}
/** Flash will not be fired. */
public static final int FLASH_OFF = Constants.FLASH_OFF;
/** Flash will always be fired during snapshot. */
public static final int FLASH_ON = Constants.FLASH_ON;
/** Constant emission of light during preview, auto-focus and snapshot. */
public static final int FLASH_TORCH = Constants.FLASH_TORCH;
/** Flash will be fired automatically when required. */
public static final int FLASH_AUTO = Constants.FLASH_AUTO;
/** Flash will be fired in red-eye reduction mode. */
public static final int FLASH_RED_EYE = Constants.FLASH_RED_EYE;
/** The mode for for the camera device's flash control */
@IntDef({FLASH_OFF, FLASH_ON, FLASH_TORCH, FLASH_AUTO, FLASH_RED_EYE})
public @interface Flash {
}
CameraViewImpl mImpl;
private final CallbackBridge mCallbacks;
private boolean mAdjustViewBounds;
private final DisplayOrientationDetector mDisplayOrientationDetector;
public CameraView(Context context) {
this(context, null);
}
public CameraView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
@SuppressWarnings("WrongConstant")
public CameraView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
if (isInEditMode()){
mCallbacks = null;
mDisplayOrientationDetector = null;
return;
}
// Internal setup
final PreviewImpl preview = createPreviewImpl(context);
mCallbacks = new CallbackBridge();
if (Build.VERSION.SDK_INT < 21) {
mImpl = new Camera1(mCallbacks, preview);
} else if (Build.VERSION.SDK_INT < 23) {
mImpl = new Camera2(mCallbacks, preview, context);
} else {
mImpl = new Camera2Api23(mCallbacks, preview, context);
}
// Attributes
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CameraView, defStyleAttr,
R.style.Widget_CameraView);
mAdjustViewBounds = a.getBoolean(R.styleable.CameraView_android_adjustViewBounds, false);
setFacing(a.getInt(R.styleable.CameraView_facing, FACING_BACK));
String aspectRatio = a.getString(R.styleable.CameraView_aspectRatio);
if (aspectRatio != null) {
setAspectRatio(AspectRatio.parse(aspectRatio));
} else {
setAspectRatio(Constants.DEFAULT_ASPECT_RATIO);
}
setAutoFocus(a.getBoolean(R.styleable.CameraView_autoFocus, true));
setFlash(a.getInt(R.styleable.CameraView_flash, Constants.FLASH_AUTO));
a.recycle();
// Display orientation detector
mDisplayOrientationDetector = new DisplayOrientationDetector(context) {
@Override
public void onDisplayOrientationChanged(int displayOrientation) {
mImpl.setDisplayOrientation(displayOrientation);
}
};
}
@NonNull
private PreviewImpl createPreviewImpl(Context context) {
PreviewImpl preview;
if (Build.VERSION.SDK_INT < 14) {
preview = new SurfaceViewPreview(context, this);
} else {
preview = new TextureViewPreview(context, this);
}
return preview;
}
@Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
if (!isInEditMode()) {
mDisplayOrientationDetector.enable(ViewCompat.getDisplay(this));
}
}
@Override
protected void onDetachedFromWindow() {
if (!isInEditMode()) {
mDisplayOrientationDetector.disable();
}
super.onDetachedFromWindow();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if (isInEditMode()){
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
return;
}
// Handle android:adjustViewBounds
if (mAdjustViewBounds) {
if (!isCameraOpened()) {
mCallbacks.reserveRequestLayoutOnOpen();
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
return;
}
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
if (widthMode == MeasureSpec.EXACTLY && heightMode != MeasureSpec.EXACTLY) {
final AspectRatio ratio = getAspectRatio();
assert ratio != null;
int height = (int) (MeasureSpec.getSize(widthMeasureSpec) * ratio.toFloat());
if (heightMode == MeasureSpec.AT_MOST) {
height = Math.min(height, MeasureSpec.getSize(heightMeasureSpec));
}
super.onMeasure(widthMeasureSpec,
MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY));
} else if (widthMode != MeasureSpec.EXACTLY && heightMode == MeasureSpec.EXACTLY) {
final AspectRatio ratio = getAspectRatio();
assert ratio != null;
int width = (int) (MeasureSpec.getSize(heightMeasureSpec) * ratio.toFloat());
if (widthMode == MeasureSpec.AT_MOST) {
width = Math.min(width, MeasureSpec.getSize(widthMeasureSpec));
}
super.onMeasure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY),
heightMeasureSpec);
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
// Measure the TextureView
int width = getMeasuredWidth();
int height = getMeasuredHeight();
AspectRatio ratio = getAspectRatio();
if (mDisplayOrientationDetector.getLastKnownDisplayOrientation() % 180 == 0) {
ratio = ratio.inverse();
}
assert ratio != null;
if (height < width * ratio.getY() / ratio.getX()) {
mImpl.getView().measure(
MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(width * ratio.getY() / ratio.getX(),
MeasureSpec.EXACTLY));
} else {
mImpl.getView().measure(
MeasureSpec.makeMeasureSpec(height * ratio.getX() / ratio.getY(),
MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY));
}
}
@Override
protected Parcelable onSaveInstanceState() {
SavedState state = new SavedState(super.onSaveInstanceState());
state.facing = getFacing();
state.ratio = getAspectRatio();
state.autoFocus = getAutoFocus();
state.flash = getFlash();
return state;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (!(state instanceof SavedState)) {
super.onRestoreInstanceState(state);
return;
}
SavedState ss = (SavedState) state;
super.onRestoreInstanceState(ss.getSuperState());
setFacing(ss.facing);
setAspectRatio(ss.ratio);
setAutoFocus(ss.autoFocus);
setFlash(ss.flash);
}
/**
* Open a camera device and start showing camera preview. This is typically called from
* {@link Activity#onResume()}.
*/
public void start() {
if (!mImpl.start()) {
//store the state ,and restore this state after fall back o Camera1
Parcelable state=onSaveInstanceState();
// Camera2 uses legacy hardware layer; fall back to Camera1
mImpl = new Camera1(mCallbacks, createPreviewImpl(getContext()));
onRestoreInstanceState(state);
mImpl.start();
}
}
/**
* Stop camera preview and close the device. This is typically called from
* {@link Activity#onPause()}.
*/
public void stop() {
mImpl.stop();
}
/**
* @return {@code true} if the camera is opened.
*/
public boolean isCameraOpened() {
return mImpl.isCameraOpened();
}
/**
* Add a new callback.
*
* @param callback The {@link Callback} to add.
* @see #removeCallback(Callback)
*/
public void addCallback(@NonNull Callback callback) {
mCallbacks.add(callback);
}
/**
* Remove a callback.
*
* @param callback The {@link Callback} to remove.
* @see #addCallback(Callback)
*/
public void removeCallback(@NonNull Callback callback) {
mCallbacks.remove(callback);
}
/**
* @param adjustViewBounds {@code true} if you want the CameraView to adjust its bounds to
* preserve the aspect ratio of camera.
* @see #getAdjustViewBounds()
*/
public void setAdjustViewBounds(boolean adjustViewBounds) {
if (mAdjustViewBounds != adjustViewBounds) {
mAdjustViewBounds = adjustViewBounds;
requestLayout();
}
}
/**
* @return True when this CameraView is adjusting its bounds to preserve the aspect ratio of
* camera.
* @see #setAdjustViewBounds(boolean)
*/
public boolean getAdjustViewBounds() {
return mAdjustViewBounds;
}
/**
* Chooses camera by the direction it faces.
*
* @param facing The camera facing. Must be either {@link #FACING_BACK} or
* {@link #FACING_FRONT}.
*/
public void setFacing(@Facing int facing) {
mImpl.setFacing(facing);
}
/**
* Gets the direction that the current camera faces.
*
* @return The camera facing.
*/
@Facing
public int getFacing() {
//noinspection WrongConstant
return mImpl.getFacing();
}
/**
* Gets all the aspect ratios supported by the current camera.
*/
public Set<AspectRatio> getSupportedAspectRatios() {
return mImpl.getSupportedAspectRatios();
}
/**
* Sets the aspect ratio of camera.
*
* @param ratio The {@link AspectRatio} to be set.
*/
public void setAspectRatio(@NonNull AspectRatio ratio) {
if (mImpl.setAspectRatio(ratio)) {
requestLayout();
}
}
/**
* Gets the current aspect ratio of camera.
*
* @return The current {@link AspectRatio}. Can be {@code null} if no camera is opened yet.
*/
@Nullable
public AspectRatio getAspectRatio() {
return mImpl.getAspectRatio();
}
/**
* Enables or disables the continuous auto-focus mode. When the current camera doesn't support
* auto-focus, calling this method will be ignored.
*
* @param autoFocus {@code true} to enable continuous auto-focus mode. {@code false} to
* disable it.
*/
public void setAutoFocus(boolean autoFocus) {
mImpl.setAutoFocus(autoFocus);
}
/**
* Returns whether the continuous auto-focus mode is enabled.
*
* @return {@code true} if the continuous auto-focus mode is enabled. {@code false} if it is
* disabled, or if it is not supported by the current camera.
*/
public boolean getAutoFocus() {
return mImpl.getAutoFocus();
}
/**
* Sets the flash mode.
*
* @param flash The desired flash mode.
*/
public void setFlash(@Flash int flash) {
mImpl.setFlash(flash);
}
/**
* Gets the current flash mode.
*
* @return The current flash mode.
*/
@Flash
public int getFlash() {
//noinspection WrongConstant
return mImpl.getFlash();
}
/**
* Take a picture. The result will be returned to
* {@link Callback#onPictureTaken(CameraView, byte[])}.
*/
public void takePicture() {
mImpl.takePicture();
}
private class CallbackBridge implements CameraViewImpl.Callback {
private final ArrayList<Callback> mCallbacks = new ArrayList<>();
private boolean mRequestLayoutOnOpen;
CallbackBridge() {
}
public void add(Callback callback) {
mCallbacks.add(callback);
}
public void remove(Callback callback) {
mCallbacks.remove(callback);
}
@Override
public void onCameraOpened() {
if (mRequestLayoutOnOpen) {
mRequestLayoutOnOpen = false;
requestLayout();
}
for (Callback callback : mCallbacks) {
callback.onCameraOpened(CameraView.this);
}
}
@Override
public void onCameraClosed() {
for (Callback callback : mCallbacks) {
callback.onCameraClosed(CameraView.this);
}
}
@Override
public void onPictureTaken(byte[] data) {
for (Callback callback : mCallbacks) {
callback.onPictureTaken(CameraView.this, data);
}
}
public void reserveRequestLayoutOnOpen() {
mRequestLayoutOnOpen = true;
}
}
protected static class SavedState extends BaseSavedState {
@Facing
int facing;
AspectRatio ratio;
boolean autoFocus;
@Flash
int flash;
@SuppressWarnings("WrongConstant")
public SavedState(Parcel source, ClassLoader loader) {
super(source);
facing = source.readInt();
ratio = source.readParcelable(loader);
autoFocus = source.readByte() != 0;
flash = source.readInt();
}
public SavedState(Parcelable superState) {
super(superState);
}
@Override
public void writeToParcel(Parcel out, int flags) {
super.writeToParcel(out, flags);
out.writeInt(facing);
out.writeParcelable(ratio, 0);
out.writeByte((byte) (autoFocus ? 1 : 0));
out.writeInt(flash);
}
public static final Parcelable.Creator<SavedState> CREATOR
= ParcelableCompat.newCreator(new ParcelableCompatCreatorCallbacks<SavedState>() {
@Override
public SavedState createFromParcel(Parcel in, ClassLoader loader) {
return new SavedState(in, loader);
}
@Override
public SavedState[] newArray(int size) {
return new SavedState[size];
}
});
}
/**
* Callback for monitoring events about {@link CameraView}.
*/
@SuppressWarnings("UnusedParameters")
public abstract static class Callback {
/**
* Called when camera is opened.
*
* @param cameraView The associated {@link CameraView}.
*/
public void onCameraOpened(CameraView cameraView) {
}
/**
* Called when camera is closed.
*
* @param cameraView The associated {@link CameraView}.
*/
public void onCameraClosed(CameraView cameraView) {
}
/**
* Called when a picture is taken.
*
* @param cameraView The associated {@link CameraView}.
* @param data JPEG data.
*/
public void onPictureTaken(CameraView cameraView, byte[] data) {
}
}
}
和xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/colorgrey">
<com.google.android.cameraview.CameraView
android:id="@+id/camera"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:adjustViewBounds="true"
android:background="@android:color/black" />
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true" />
<ImageButton
android:id="@+id/take_picture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="20dp"
android:background="#0000"
app:srcCompat="@drawable/ic_take_pic" />
<ImageButton
android:id="@+id/btn_switch_camera"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_margin="20dp"
android:background="#0000"
app:srcCompat="@drawable/ic_reset_camera" />
<ImageButton
android:id="@+id/btn_flash_onOff"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_margin="20dp"
android:background="#0000"
app:srcCompat="@drawable/ic_flash_off" />
</RelativeLayout>
另外不要忘记在 OnCreate() 中添加运行时权限