Gradle 使用 Google 的最新 API 时出错
Gradle error when using Google's latest API
我正在使用 Google Vision API 的示例在现有项目的网络视图中制作条形码 reader。
https://github.com/googlesamples/android-vision/tree/master/visionSamples/barcode-reader
这是我的错误信息：
Error:(36, 13) Failed to resolve: com.google.android.support:design:23.0.1
这是 build.gradle 文件：
apply plugin: 'com.android.application'
android {
compileSdkVersion 23
buildToolsVersion "21.1.2"
defaultConfig {
applicationId "com.example.harry"
minSdkVersion 15
targetSdkVersion 23
versionCode 1
versionName "1.0"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
packagingOptions {
exclude 'META-INF/DEPENDENCIES'
exclude 'META-INF/LICENSE'
exclude 'META-INF/LICENSE.txt'
exclude 'META-INF/license.txt'
exclude 'META-INF/NOTICE'
exclude 'META-INF/NOTICE.txt'
exclude 'META-INF/notice.txt'
exclude 'META-INF/ASL2.0'
}
}
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
compile 'com.android.support:support-v4:23.0.1'
compile 'com.google.android.gms:play-services:8.1.0'
compile 'com.google.android.support:design:23.0.1'
compile files('libs/android-support-v4.jar')
compile files('libs/httpclient-4.3.6.jar')
compile files('libs/commons-codec-1.3.jar')
compile files('libs/httpclient-4.1-beta1.jar')
compile files('libs/apache-mime4j-0.6.jar')
compile files('libs/httpclient-4.1.jar')
compile files('libs/httpcore-4.1.jar')
compile project(':..:ExpandableButtonMenu:library')
}
当我创建 BarcodeCaptureActivity.java 时，
我收到很多错误...
BarcodeCaptureActivity.java:
package com.example.harry;
import android.Manifest;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GoogleApiAvailability;
import com.google.android.gms.common.api.CommonStatusCodes;
import com.google.android.gms.samples.vision.barcodereader.ui.camera.CameraSource;
import com.google.android.gms.samples.vision.barcodereader.ui.camera.CameraSourcePreview;
import com.google.android.gms.samples.vision.barcodereader.ui.camera.GraphicOverlay;
import com.google.android.gms.vision.MultiProcessor;
import com.google.android.gms.vision.barcode.Barcode;
import com.google.android.gms.vision.barcode.BarcodeDetector;
import java.io.IOException;
public class BarcodeCaptureActivity extends ActionBarActivity {
private static final String TAG = "Barcode-reader";
// intent request code to handle updating play services if needed.
private static final int RC_HANDLE_GMS = 9001;
// permission request codes need to be < 256
private static final int RC_HANDLE_CAMERA_PERM = 2;
// constants used to pass extra data in the intent
public static final String AutoFocus = "AutoFocus";
public static final String UseFlash = "UseFlash";
public static final String BarcodeObject = "Barcode";
private CameraSource mCameraSource;
private CameraSourcePreview mPreview;
private GraphicOverlay<BarcodeGraphic> mGraphicOverlay;
// helper objects for detecting taps and pinches.
private ScaleGestureDetector scaleGestureDetector;
private GestureDetector gestureDetector;
/**
* Initializes the UI and creates the detector pipeline.
*/
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.barcode_capture);
mPreview = (CameraSourcePreview) findViewById(R.id.preview);
mGraphicOverlay = (GraphicOverlay<BarcodeGraphic>) findViewById(R.id.graphicOverlay);
// read parameters from the intent used to launch the activity.
boolean autoFocus = getIntent().getBooleanExtra(AutoFocus, false);
boolean useFlash = getIntent().getBooleanExtra(UseFlash, false);
// Check for the camera permission before accessing the camera. If the
// permission is not granted yet, request permission.
int rc = ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA);
if (rc == PackageManager.PERMISSION_GRANTED) {
createCameraSource(autoFocus, useFlash);
} else {
requestCameraPermission();
}
gestureDetector = new GestureDetector(this, new CaptureGestureListener());
scaleGestureDetector = new ScaleGestureDetector(this, new ScaleListener());
Snackbar.make(mGraphicOverlay, "Tap to capture. Pinch/Stretch to zoom",
Snackbar.LENGTH_LONG)
.show();
}
/**
* Handles the requesting of the camera permission. This includes
* showing a "Snackbar" message of why the permission is needed then
* sending the request.
*/
private void requestCameraPermission() {
Log.w(TAG, "Camera permission is not granted. Requesting permission");
final String[] permissions = new String[]{Manifest.permission.CAMERA};
if (!ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.CAMERA)) {
ActivityCompat.requestPermissions(this, permissions, RC_HANDLE_CAMERA_PERM);
return;
}
final Activity thisActivity = this;
View.OnClickListener listener = new View.OnClickListener() {
@Override
public void onClick(View view) {
ActivityCompat.requestPermissions(thisActivity, permissions,
RC_HANDLE_CAMERA_PERM);
}
};
Snackbar.make(mGraphicOverlay, R.string.permission_camera_rationale,
Snackbar.LENGTH_INDEFINITE)
.setAction(R.string.ok, listener)
.show();
}
@Override
public boolean onTouchEvent(MotionEvent e) {
boolean b = scaleGestureDetector.onTouchEvent(e);
boolean c = gestureDetector.onTouchEvent(e);
return b || c || super.onTouchEvent(e);
}
/**
* Creates and starts the camera. Note that this uses a higher resolution in comparison
* to other detection examples to enable the barcode detector to detect small barcodes
* at long distances.
*
* Suppressing InlinedApi since there is a check that the minimum version is met before using
* the constant.
*/
@SuppressLint("InlinedApi")
private void createCameraSource(boolean autoFocus, boolean useFlash) {
Context context = getApplicationContext();
// A barcode detector is created to track barcodes. An associated multi-processor instance
// is set to receive the barcode detection results, track the barcodes, and maintain
// graphics for each barcode on screen. The factory is used by the multi-processor to
// create a separate tracker instance for each barcode.
BarcodeDetector barcodeDetector = new BarcodeDetector.Builder(context).build();
BarcodeTrackerFactory barcodeFactory = new BarcodeTrackerFactory(mGraphicOverlay);
barcodeDetector.setProcessor(
new MultiProcessor.Builder<>(barcodeFactory).build());
if (!barcodeDetector.isOperational()) {
// Note: The first time that an app using the barcode or face API is installed on a
// device, GMS will download a native libraries to the device in order to do detection.
// Usually this completes before the app is run for the first time. But if that
// download has not yet completed, then the above call will not detect any barcodes
// and/or faces.
//
// isOperational() can be used to check if the required native libraries are currently
// available. The detectors will automatically become operational once the library
// downloads complete on device.
Log.w(TAG, "Detector dependencies are not yet available.");
// Check for low storage. If there is low storage, the native library will not be
// downloaded, so detection will not become operational.
IntentFilter lowstorageFilter = new IntentFilter(Intent.ACTION_DEVICE_STORAGE_LOW);
boolean hasLowStorage = registerReceiver(null, lowstorageFilter) != null;
if (hasLowStorage) {
Toast.makeText(this, R.string.low_storage_error, Toast.LENGTH_LONG).show();
Log.w(TAG, getString(R.string.low_storage_error));
}
}
// Creates and starts the camera. Note that this uses a higher resolution in comparison
// to other detection examples to enable the barcode detector to detect small barcodes
// at long distances.
CameraSource.Builder builder = new CameraSource.Builder(getApplicationContext(), barcodeDetector)
.setFacing(CameraSource.CAMERA_FACING_BACK)
.setRequestedPreviewSize(1600, 1024)
.setRequestedFps(15.0f);
// make sure that auto focus is an available option
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
builder = builder.setFocusMode(
autoFocus ? Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE : null);
}
mCameraSource = builder
.setFlashMode(useFlash ? Camera.Parameters.FLASH_MODE_TORCH : null)
.build();
}
/**
* Restarts the camera.
*/
@Override
protected void onResume() {
super.onResume();
startCameraSource();
}
/**
* Stops the camera.
*/
@Override
protected void onPause() {
super.onPause();
if (mPreview != null) {
mPreview.stop();
}
}
/**
* Releases the resources associated with the camera source, the associated detectors, and the
* rest of the processing pipeline.
*/
@Override
protected void onDestroy() {
super.onDestroy();
if (mPreview != null) {
mPreview.release();
}
}
/**
* Callback for the result from requesting permissions. This method
* is invoked for every call on {@link #requestPermissions(String[], int)}.
* <p>
* <strong>Note:</strong> It is possible that the permissions request interaction
* with the user is interrupted. In this case you will receive empty permissions
* and results arrays which should be treated as a cancellation.
* </p>
*
* @param requestCode The request code passed in {@link #requestPermissions(String[], int)}.
* @param permissions The requested permissions. Never null.
* @param grantResults The grant results for the corresponding permissions
* which is either {@link PackageManager#PERMISSION_GRANTED}
* or {@link PackageManager#PERMISSION_DENIED}. Never null.
* @see #requestPermissions(String[], int)
*/
@Override
public void onRequestPermissionsResult(int requestCode,
@NonNull String[] permissions,
@NonNull int[] grantResults) {
if (requestCode != RC_HANDLE_CAMERA_PERM) {
Log.d(TAG, "Got unexpected permission result: " + requestCode);
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
return;
}
if (grantResults.length != 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Log.d(TAG, "Camera permission granted - initialize the camera source");
// we have permission, so create the camerasource
boolean autoFocus = getIntent().getBooleanExtra(AutoFocus,false);
boolean useFlash = getIntent().getBooleanExtra(UseFlash, false);
createCameraSource(autoFocus, useFlash);
return;
}
Log.e(TAG, "Permission not granted: results len = " + grantResults.length +
" Result code = " + (grantResults.length > 0 ? grantResults[0] : "(empty)"));
DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
finish();
}
};
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Multitracker sample")
.setMessage(R.string.no_camera_permission)
.setPositiveButton(R.string.ok, listener)
.show();
}
/**
* Starts or restarts the camera source, if it exists. If the camera source doesn't exist yet
* (e.g., because onResume was called before the camera source was created), this will be called
* again when the camera source is created.
*/
private void startCameraSource() throws SecurityException {
// check that the device has play services available.
int code = GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(
getApplicationContext());
if (code != ConnectionResult.SUCCESS) {
Dialog dlg =
GoogleApiAvailability.getInstance().getErrorDialog(this, code, RC_HANDLE_GMS);
dlg.show();
}
if (mCameraSource != null) {
try {
mPreview.start(mCameraSource, mGraphicOverlay);
} catch (IOException e) {
Log.e(TAG, "Unable to start camera source.", e);
mCameraSource.release();
mCameraSource = null;
}
}
}
/**
* onTap is called to capture the oldest barcode currently detected and
* return it to the caller.
*
* @param rawX - the raw position of the tap
* @param rawY - the raw position of the tap.
* @return true if the activity is ending.
*/
private boolean onTap(float rawX, float rawY) {
//TODO: use the tap position to select the barcode.
BarcodeGraphic graphic = mGraphicOverlay.getFirstGraphic();
Barcode barcode = null;
if (graphic != null) {
barcode = graphic.getBarcode();
if (barcode != null) {
Intent data = new Intent();
data.putExtra(BarcodeObject, barcode);
setResult(CommonStatusCodes.SUCCESS, data);
finish();
}
else {
Log.d(TAG, "barcode data is null");
}
}
else {
Log.d(TAG,"no barcode detected");
}
return barcode != null;
}
private class CaptureGestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
return onTap(e.getRawX(), e.getRawY()) || super.onSingleTapConfirmed(e);
}
}
private class ScaleListener implements ScaleGestureDetector.OnScaleGestureListener {
/**
* Responds to scaling events for a gesture in progress.
* Reported by pointer motion.
*
* @param detector The detector reporting the event - use this to
* retrieve extended info about event state.
* @return Whether or not the detector should consider this event
* as handled. If an event was not handled, the detector
* will continue to accumulate movement until an event is
* handled. This can be useful if an application, for example,
* only wants to update scaling factors if the change is
* greater than 0.01.
*/
@Override
public boolean onScale(ScaleGestureDetector detector) {
return false;
}
/**
* Responds to the beginning of a scaling gesture. Reported by
* new pointers going down.
*
* @param detector The detector reporting the event - use this to
* retrieve extended info about event state.
* @return Whether or not the detector should continue recognizing
* this gesture. For example, if a gesture is beginning
* with a focal point outside of a region where it makes
* sense, onScaleBegin() may return false to ignore the
* rest of the gesture.
*/
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
return true;
}
/**
* Responds to the end of a scale gesture. Reported by existing
* pointers going up.
* <p/>
* Once a scale has ended, {@link ScaleGestureDetector#getFocusX()}
* and {@link ScaleGestureDetector#getFocusY()} will return focal point
* of the pointers remaining on the screen.
*
* @param detector The detector reporting the event - use this to
* retrieve extended info about event state.
*/
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
mCameraSource.doZoom(detector.getScaleFactor());
}
}
}
}
为什么 android 工作室无法识别 java 中的导入？
我被困在这里2天了...
请帮助我！！！
您的错误是因为导入语句引用了 Github 示例中的项目文件。 com.google.android.gms.samples.vision.barcodereader.ui.camera.CameraSource; 等都引用示例中的文件，这些文件不存在于您的项目中。当您导入某些内容时，它会沿着路径向下找到文件名，因此它目前正在尝试通过在它前面列出的文件夹中向下查找文件 CameraSource。这些特定于 Android 个项目，因此您应该从示例项目中复制任何需要的文件，然后在您自己的项目中重新创建它们。
创建它们后，您可以导入这些而不是示例（即将 com.google.android.gms.samples.vision.barcodereader.ui.camera.CameraSource; 替换为 com.your.package.name.barcodereader 等）Android Studio 会在您开始输入时建议导入所以更容易定位。
如果您仍然遇到问题，请告诉我:)
编辑 - 作为旁注，如果您试图从 Github 运行 自己获取示例 Android 项目，而不是复制和粘贴（这可能会导致严重头痛）
a) 使用 git 克隆项目源代码（Android Studio 的内置功能，参见 youtube guide here）
或
b) 将 github 存储库下载到一个 zip 文件，解压然后在 Android Studio 中打开它。 （可能需要一些 SDK / Gradle 修复）
选项 b 的步骤是：
- 在 github 存储库页面（顶级）上，单击文件列表上方右侧的下载 zip。
- 解压下载的文件夹
- 打开 Android Studio 和 select > 打开一个现有的 Android Studio 项目
- 找到您提取的文件夹（请注意，如果文件夹中有多个项目，如本例，您必须 select 您想要的文件夹。在本例中，它是 visionSample/barcode-reader )
- Android Studio 会将此文件夹导入为 Android Studio 项目，如果未安装所需的 Gradle 插件/SDK 工具（从 SDK 安装它们），可能会显示一些错误经理）
这两个选项都可以让您比传统的复制和粘贴更快地测试应用程序。
我正在使用 Google Vision API 的示例在现有项目的网络视图中制作条形码 reader。 https://github.com/googlesamples/android-vision/tree/master/visionSamples/barcode-reader
这是我的错误信息：
Error:(36, 13) Failed to resolve: com.google.android.support:design:23.0.1
这是 build.gradle 文件：
apply plugin: 'com.android.application'
android {
compileSdkVersion 23
buildToolsVersion "21.1.2"
defaultConfig {
applicationId "com.example.harry"
minSdkVersion 15
targetSdkVersion 23
versionCode 1
versionName "1.0"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
packagingOptions {
exclude 'META-INF/DEPENDENCIES'
exclude 'META-INF/LICENSE'
exclude 'META-INF/LICENSE.txt'
exclude 'META-INF/license.txt'
exclude 'META-INF/NOTICE'
exclude 'META-INF/NOTICE.txt'
exclude 'META-INF/notice.txt'
exclude 'META-INF/ASL2.0'
}
}
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
compile 'com.android.support:support-v4:23.0.1'
compile 'com.google.android.gms:play-services:8.1.0'
compile 'com.google.android.support:design:23.0.1'
compile files('libs/android-support-v4.jar')
compile files('libs/httpclient-4.3.6.jar')
compile files('libs/commons-codec-1.3.jar')
compile files('libs/httpclient-4.1-beta1.jar')
compile files('libs/apache-mime4j-0.6.jar')
compile files('libs/httpclient-4.1.jar')
compile files('libs/httpcore-4.1.jar')
compile project(':..:ExpandableButtonMenu:library')
}
当我创建 BarcodeCaptureActivity.java 时， 我收到很多错误... BarcodeCaptureActivity.java:
package com.example.harry;
import android.Manifest;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GoogleApiAvailability;
import com.google.android.gms.common.api.CommonStatusCodes;
import com.google.android.gms.samples.vision.barcodereader.ui.camera.CameraSource;
import com.google.android.gms.samples.vision.barcodereader.ui.camera.CameraSourcePreview;
import com.google.android.gms.samples.vision.barcodereader.ui.camera.GraphicOverlay;
import com.google.android.gms.vision.MultiProcessor;
import com.google.android.gms.vision.barcode.Barcode;
import com.google.android.gms.vision.barcode.BarcodeDetector;
import java.io.IOException;
public class BarcodeCaptureActivity extends ActionBarActivity {
private static final String TAG = "Barcode-reader";
// intent request code to handle updating play services if needed.
private static final int RC_HANDLE_GMS = 9001;
// permission request codes need to be < 256
private static final int RC_HANDLE_CAMERA_PERM = 2;
// constants used to pass extra data in the intent
public static final String AutoFocus = "AutoFocus";
public static final String UseFlash = "UseFlash";
public static final String BarcodeObject = "Barcode";
private CameraSource mCameraSource;
private CameraSourcePreview mPreview;
private GraphicOverlay<BarcodeGraphic> mGraphicOverlay;
// helper objects for detecting taps and pinches.
private ScaleGestureDetector scaleGestureDetector;
private GestureDetector gestureDetector;
/**
* Initializes the UI and creates the detector pipeline.
*/
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.barcode_capture);
mPreview = (CameraSourcePreview) findViewById(R.id.preview);
mGraphicOverlay = (GraphicOverlay<BarcodeGraphic>) findViewById(R.id.graphicOverlay);
// read parameters from the intent used to launch the activity.
boolean autoFocus = getIntent().getBooleanExtra(AutoFocus, false);
boolean useFlash = getIntent().getBooleanExtra(UseFlash, false);
// Check for the camera permission before accessing the camera. If the
// permission is not granted yet, request permission.
int rc = ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA);
if (rc == PackageManager.PERMISSION_GRANTED) {
createCameraSource(autoFocus, useFlash);
} else {
requestCameraPermission();
}
gestureDetector = new GestureDetector(this, new CaptureGestureListener());
scaleGestureDetector = new ScaleGestureDetector(this, new ScaleListener());
Snackbar.make(mGraphicOverlay, "Tap to capture. Pinch/Stretch to zoom",
Snackbar.LENGTH_LONG)
.show();
}
/**
* Handles the requesting of the camera permission. This includes
* showing a "Snackbar" message of why the permission is needed then
* sending the request.
*/
private void requestCameraPermission() {
Log.w(TAG, "Camera permission is not granted. Requesting permission");
final String[] permissions = new String[]{Manifest.permission.CAMERA};
if (!ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.CAMERA)) {
ActivityCompat.requestPermissions(this, permissions, RC_HANDLE_CAMERA_PERM);
return;
}
final Activity thisActivity = this;
View.OnClickListener listener = new View.OnClickListener() {
@Override
public void onClick(View view) {
ActivityCompat.requestPermissions(thisActivity, permissions,
RC_HANDLE_CAMERA_PERM);
}
};
Snackbar.make(mGraphicOverlay, R.string.permission_camera_rationale,
Snackbar.LENGTH_INDEFINITE)
.setAction(R.string.ok, listener)
.show();
}
@Override
public boolean onTouchEvent(MotionEvent e) {
boolean b = scaleGestureDetector.onTouchEvent(e);
boolean c = gestureDetector.onTouchEvent(e);
return b || c || super.onTouchEvent(e);
}
/**
* Creates and starts the camera. Note that this uses a higher resolution in comparison
* to other detection examples to enable the barcode detector to detect small barcodes
* at long distances.
*
* Suppressing InlinedApi since there is a check that the minimum version is met before using
* the constant.
*/
@SuppressLint("InlinedApi")
private void createCameraSource(boolean autoFocus, boolean useFlash) {
Context context = getApplicationContext();
// A barcode detector is created to track barcodes. An associated multi-processor instance
// is set to receive the barcode detection results, track the barcodes, and maintain
// graphics for each barcode on screen. The factory is used by the multi-processor to
// create a separate tracker instance for each barcode.
BarcodeDetector barcodeDetector = new BarcodeDetector.Builder(context).build();
BarcodeTrackerFactory barcodeFactory = new BarcodeTrackerFactory(mGraphicOverlay);
barcodeDetector.setProcessor(
new MultiProcessor.Builder<>(barcodeFactory).build());
if (!barcodeDetector.isOperational()) {
// Note: The first time that an app using the barcode or face API is installed on a
// device, GMS will download a native libraries to the device in order to do detection.
// Usually this completes before the app is run for the first time. But if that
// download has not yet completed, then the above call will not detect any barcodes
// and/or faces.
//
// isOperational() can be used to check if the required native libraries are currently
// available. The detectors will automatically become operational once the library
// downloads complete on device.
Log.w(TAG, "Detector dependencies are not yet available.");
// Check for low storage. If there is low storage, the native library will not be
// downloaded, so detection will not become operational.
IntentFilter lowstorageFilter = new IntentFilter(Intent.ACTION_DEVICE_STORAGE_LOW);
boolean hasLowStorage = registerReceiver(null, lowstorageFilter) != null;
if (hasLowStorage) {
Toast.makeText(this, R.string.low_storage_error, Toast.LENGTH_LONG).show();
Log.w(TAG, getString(R.string.low_storage_error));
}
}
// Creates and starts the camera. Note that this uses a higher resolution in comparison
// to other detection examples to enable the barcode detector to detect small barcodes
// at long distances.
CameraSource.Builder builder = new CameraSource.Builder(getApplicationContext(), barcodeDetector)
.setFacing(CameraSource.CAMERA_FACING_BACK)
.setRequestedPreviewSize(1600, 1024)
.setRequestedFps(15.0f);
// make sure that auto focus is an available option
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
builder = builder.setFocusMode(
autoFocus ? Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE : null);
}
mCameraSource = builder
.setFlashMode(useFlash ? Camera.Parameters.FLASH_MODE_TORCH : null)
.build();
}
/**
* Restarts the camera.
*/
@Override
protected void onResume() {
super.onResume();
startCameraSource();
}
/**
* Stops the camera.
*/
@Override
protected void onPause() {
super.onPause();
if (mPreview != null) {
mPreview.stop();
}
}
/**
* Releases the resources associated with the camera source, the associated detectors, and the
* rest of the processing pipeline.
*/
@Override
protected void onDestroy() {
super.onDestroy();
if (mPreview != null) {
mPreview.release();
}
}
/**
* Callback for the result from requesting permissions. This method
* is invoked for every call on {@link #requestPermissions(String[], int)}.
* <p>
* <strong>Note:</strong> It is possible that the permissions request interaction
* with the user is interrupted. In this case you will receive empty permissions
* and results arrays which should be treated as a cancellation.
* </p>
*
* @param requestCode The request code passed in {@link #requestPermissions(String[], int)}.
* @param permissions The requested permissions. Never null.
* @param grantResults The grant results for the corresponding permissions
* which is either {@link PackageManager#PERMISSION_GRANTED}
* or {@link PackageManager#PERMISSION_DENIED}. Never null.
* @see #requestPermissions(String[], int)
*/
@Override
public void onRequestPermissionsResult(int requestCode,
@NonNull String[] permissions,
@NonNull int[] grantResults) {
if (requestCode != RC_HANDLE_CAMERA_PERM) {
Log.d(TAG, "Got unexpected permission result: " + requestCode);
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
return;
}
if (grantResults.length != 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Log.d(TAG, "Camera permission granted - initialize the camera source");
// we have permission, so create the camerasource
boolean autoFocus = getIntent().getBooleanExtra(AutoFocus,false);
boolean useFlash = getIntent().getBooleanExtra(UseFlash, false);
createCameraSource(autoFocus, useFlash);
return;
}
Log.e(TAG, "Permission not granted: results len = " + grantResults.length +
" Result code = " + (grantResults.length > 0 ? grantResults[0] : "(empty)"));
DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
finish();
}
};
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Multitracker sample")
.setMessage(R.string.no_camera_permission)
.setPositiveButton(R.string.ok, listener)
.show();
}
/**
* Starts or restarts the camera source, if it exists. If the camera source doesn't exist yet
* (e.g., because onResume was called before the camera source was created), this will be called
* again when the camera source is created.
*/
private void startCameraSource() throws SecurityException {
// check that the device has play services available.
int code = GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(
getApplicationContext());
if (code != ConnectionResult.SUCCESS) {
Dialog dlg =
GoogleApiAvailability.getInstance().getErrorDialog(this, code, RC_HANDLE_GMS);
dlg.show();
}
if (mCameraSource != null) {
try {
mPreview.start(mCameraSource, mGraphicOverlay);
} catch (IOException e) {
Log.e(TAG, "Unable to start camera source.", e);
mCameraSource.release();
mCameraSource = null;
}
}
}
/**
* onTap is called to capture the oldest barcode currently detected and
* return it to the caller.
*
* @param rawX - the raw position of the tap
* @param rawY - the raw position of the tap.
* @return true if the activity is ending.
*/
private boolean onTap(float rawX, float rawY) {
//TODO: use the tap position to select the barcode.
BarcodeGraphic graphic = mGraphicOverlay.getFirstGraphic();
Barcode barcode = null;
if (graphic != null) {
barcode = graphic.getBarcode();
if (barcode != null) {
Intent data = new Intent();
data.putExtra(BarcodeObject, barcode);
setResult(CommonStatusCodes.SUCCESS, data);
finish();
}
else {
Log.d(TAG, "barcode data is null");
}
}
else {
Log.d(TAG,"no barcode detected");
}
return barcode != null;
}
private class CaptureGestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
return onTap(e.getRawX(), e.getRawY()) || super.onSingleTapConfirmed(e);
}
}
private class ScaleListener implements ScaleGestureDetector.OnScaleGestureListener {
/**
* Responds to scaling events for a gesture in progress.
* Reported by pointer motion.
*
* @param detector The detector reporting the event - use this to
* retrieve extended info about event state.
* @return Whether or not the detector should consider this event
* as handled. If an event was not handled, the detector
* will continue to accumulate movement until an event is
* handled. This can be useful if an application, for example,
* only wants to update scaling factors if the change is
* greater than 0.01.
*/
@Override
public boolean onScale(ScaleGestureDetector detector) {
return false;
}
/**
* Responds to the beginning of a scaling gesture. Reported by
* new pointers going down.
*
* @param detector The detector reporting the event - use this to
* retrieve extended info about event state.
* @return Whether or not the detector should continue recognizing
* this gesture. For example, if a gesture is beginning
* with a focal point outside of a region where it makes
* sense, onScaleBegin() may return false to ignore the
* rest of the gesture.
*/
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
return true;
}
/**
* Responds to the end of a scale gesture. Reported by existing
* pointers going up.
* <p/>
* Once a scale has ended, {@link ScaleGestureDetector#getFocusX()}
* and {@link ScaleGestureDetector#getFocusY()} will return focal point
* of the pointers remaining on the screen.
*
* @param detector The detector reporting the event - use this to
* retrieve extended info about event state.
*/
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
mCameraSource.doZoom(detector.getScaleFactor());
}
}
}
}
为什么 android 工作室无法识别 java 中的导入？
我被困在这里2天了... 请帮助我！！！
您的错误是因为导入语句引用了 Github 示例中的项目文件。 com.google.android.gms.samples.vision.barcodereader.ui.camera.CameraSource; 等都引用示例中的文件，这些文件不存在于您的项目中。当您导入某些内容时，它会沿着路径向下找到文件名，因此它目前正在尝试通过在它前面列出的文件夹中向下查找文件 CameraSource。这些特定于 Android 个项目，因此您应该从示例项目中复制任何需要的文件，然后在您自己的项目中重新创建它们。
创建它们后，您可以导入这些而不是示例（即将 com.google.android.gms.samples.vision.barcodereader.ui.camera.CameraSource; 替换为 com.your.package.name.barcodereader 等）Android Studio 会在您开始输入时建议导入所以更容易定位。
如果您仍然遇到问题，请告诉我:)
编辑 - 作为旁注，如果您试图从 Github 运行 自己获取示例 Android 项目，而不是复制和粘贴（这可能会导致严重头痛）
a) 使用 git 克隆项目源代码（Android Studio 的内置功能，参见 youtube guide here）
或
b) 将 github 存储库下载到一个 zip 文件，解压然后在 Android Studio 中打开它。 （可能需要一些 SDK / Gradle 修复）
选项 b 的步骤是：
- 在 github 存储库页面（顶级）上，单击文件列表上方右侧的下载 zip。
- 解压下载的文件夹
- 打开 Android Studio 和 select > 打开一个现有的 Android Studio 项目
- 找到您提取的文件夹（请注意，如果文件夹中有多个项目，如本例，您必须 select 您想要的文件夹。在本例中，它是 visionSample/barcode-reader )
- Android Studio 会将此文件夹导入为 Android Studio 项目，如果未安装所需的 Gradle 插件/SDK 工具（从 SDK 安装它们），可能会显示一些错误经理）
这两个选项都可以让您比传统的复制和粘贴更快地测试应用程序。