如何在onActivityresult中获取图片路径（Intent数据为null）
How to get path of picture in onActivityresult (Intent data is null)
我必须启动相机，当用户完成图片后，我必须拍摄并显示在视图中。
正在查看http://developer.android.com/guide/topics/media/camera.html我已经完成了：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bLaunchCamera = (Button) findViewById(R.id.launchCamera);
bLaunchCamera.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d(TAG, "lanzando camara");
//create intent to launch camera
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
imageUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); //create a file to save the image
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri); //set the image file name
//start camera
startActivityForResult(intent, CAMERA_REQUEST);
}
});
/**
* Create a File Uri for saving image (can be sued to save video to)
**/
private Uri getOutputMediaFileUri(int mediaTypeImage) {
return Uri.fromFile(getOutputMediaFile(mediaTypeImage));
}
/**
* Create a File for saving image (can be sued to save video to)
**/
private File getOutputMediaFile(int mediaType) {
//To be safe, is necessary to check if SDCard is mounted
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
(String) getResources().getText(R.string.app_name));
//create the storage directory if it does not exist
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d(TAG, "failed to create directory");
return null;
}
}
//Create a media file name
String timeStamp = new SimpleDateFormat("ddMMyyyy_HHmmss").format(new Date());
File mediaFile;
if (mediaType == MEDIA_TYPE_IMAGE) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg");
} else {
return null;
}
return mediaFile;
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode == CAMERA_REQUEST) {
if(resultCode == RESULT_OK) {
//Image captured and saved to fileUri specified in Intent
Toast.makeText(this, "image saved to:\n" + data.getData(), Toast.LENGTH_LONG).show();
Log.d(TAG, "lanzando camara");
} else if(resultCode == RESULT_CANCELED) {
//user cancelled the image capture;
Log.d(TAG, "usuario a cancelado la captura");
} else {
//image capture failed, advise user;
Log.d(TAG, "algo a fallado");
}
}
}
图片完成后，应用程序在尝试发送 'Toast' 信息时崩溃，因为 'data' 为空。
但如果我调试应用程序，我可以看到图像已保存。
所以我的问题是：如何在 onActivityResult 中获取路径？
这是我用于捕获和保存相机图像然后将其显示到 imageview 的代码。大家可以根据需要使用。
您必须将相机图像保存到特定位置，然后从该位置获取，然后将其转换为字节数组。
这里是打开捕获摄像头图像的方法activity。
private static final int CAMERA_PHOTO = 111;
private Uri imageToUploadUri;
private void captureCameraImage() {
Intent chooserIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
File f = new File(Environment.getExternalStorageDirectory(), "POST_IMAGE.jpg");
chooserIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f));
imageToUploadUri = Uri.fromFile(f);
startActivityForResult(chooserIntent, CAMERA_PHOTO);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CAMERA_PHOTO && resultCode == Activity.RESULT_OK) {
if(imageToUploadUri != null){
Uri selectedImage = imageToUploadUri;
getContentResolver().notifyChange(selectedImage, null);
Bitmap reducedSizeBitmap = getBitmap(imageToUploadUri.getPath());
if(reducedSizeBitmap != null){
ImgPhoto.setImageBitmap(reducedSizeBitmap);
Button uploadImageButton = (Button) findViewById(R.id.uploadUserImageButton);
uploadImageButton.setVisibility(View.VISIBLE);
}else{
Toast.makeText(this,"Error while capturing Image",Toast.LENGTH_LONG).show();
}
}else{
Toast.makeText(this,"Error while capturing Image",Toast.LENGTH_LONG).show();
}
}
}
这里是在 onActivityResult() 中使用的 getBitmap() 方法。在获取相机捕获图像位图时，我已经完成了所有可能的性能改进。
private Bitmap getBitmap(String path) {
Uri uri = Uri.fromFile(new File(path));
InputStream in = null;
try {
final int IMAGE_MAX_SIZE = 1200000; // 1.2MP
in = getContentResolver().openInputStream(uri);
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(in, null, o);
in.close();
int scale = 1;
while ((o.outWidth * o.outHeight) * (1 / Math.pow(scale, 2)) >
IMAGE_MAX_SIZE) {
scale++;
}
Log.d("", "scale = " + scale + ", orig-width: " + o.outWidth + ", orig-height: " + o.outHeight);
Bitmap b = null;
in = getContentResolver().openInputStream(uri);
if (scale > 1) {
scale--;
// scale to max possible inSampleSize that still yields an image
// larger than target
o = new BitmapFactory.Options();
o.inSampleSize = scale;
b = BitmapFactory.decodeStream(in, null, o);
// resize to desired dimensions
int height = b.getHeight();
int width = b.getWidth();
Log.d("", "1th scale operation dimenions - width: " + width + ", height: " + height);
double y = Math.sqrt(IMAGE_MAX_SIZE
/ (((double) width) / height));
double x = (y / height) * width;
Bitmap scaledBitmap = Bitmap.createScaledBitmap(b, (int) x,
(int) y, true);
b.recycle();
b = scaledBitmap;
System.gc();
} else {
b = BitmapFactory.decodeStream(in);
}
in.close();
Log.d("", "bitmap size - width: " + b.getWidth() + ", height: " +
b.getHeight());
return b;
} catch (IOException e) {
Log.e("", e.getMessage(), e);
return null;
}
}
希望对您有所帮助！
您面临的问题是，每当我们 select 来自相机意图的图像时，它可能会完成调用它的 activity，因此您创建的 imageUri 对象将是null 而你 return.
所以你需要在退出activity（进入相机意图）时保存它，就像这样-
/**
* Here we store the file url as it will be null after returning from camera
* app
*/
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// save file url in bundle as it will be null on screen orientation
// changes
outState.putParcelable("file_uri", mImageUri);
}
并在您返回 activity -
时将其取回
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
// get the file url
mImageUri = savedInstanceState.getParcelable("file_uri");
}
您的代码看起来不错，您只需在其中添加此更改即可。
我必须启动相机，当用户完成图片后，我必须拍摄并显示在视图中。
正在查看http://developer.android.com/guide/topics/media/camera.html我已经完成了：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bLaunchCamera = (Button) findViewById(R.id.launchCamera);
bLaunchCamera.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d(TAG, "lanzando camara");
//create intent to launch camera
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
imageUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); //create a file to save the image
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri); //set the image file name
//start camera
startActivityForResult(intent, CAMERA_REQUEST);
}
});
/**
* Create a File Uri for saving image (can be sued to save video to)
**/
private Uri getOutputMediaFileUri(int mediaTypeImage) {
return Uri.fromFile(getOutputMediaFile(mediaTypeImage));
}
/**
* Create a File for saving image (can be sued to save video to)
**/
private File getOutputMediaFile(int mediaType) {
//To be safe, is necessary to check if SDCard is mounted
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
(String) getResources().getText(R.string.app_name));
//create the storage directory if it does not exist
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d(TAG, "failed to create directory");
return null;
}
}
//Create a media file name
String timeStamp = new SimpleDateFormat("ddMMyyyy_HHmmss").format(new Date());
File mediaFile;
if (mediaType == MEDIA_TYPE_IMAGE) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg");
} else {
return null;
}
return mediaFile;
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode == CAMERA_REQUEST) {
if(resultCode == RESULT_OK) {
//Image captured and saved to fileUri specified in Intent
Toast.makeText(this, "image saved to:\n" + data.getData(), Toast.LENGTH_LONG).show();
Log.d(TAG, "lanzando camara");
} else if(resultCode == RESULT_CANCELED) {
//user cancelled the image capture;
Log.d(TAG, "usuario a cancelado la captura");
} else {
//image capture failed, advise user;
Log.d(TAG, "algo a fallado");
}
}
}
图片完成后，应用程序在尝试发送 'Toast' 信息时崩溃，因为 'data' 为空。
但如果我调试应用程序，我可以看到图像已保存。
所以我的问题是：如何在 onActivityResult 中获取路径？
这是我用于捕获和保存相机图像然后将其显示到 imageview 的代码。大家可以根据需要使用。
您必须将相机图像保存到特定位置，然后从该位置获取，然后将其转换为字节数组。
这里是打开捕获摄像头图像的方法activity。
private static final int CAMERA_PHOTO = 111;
private Uri imageToUploadUri;
private void captureCameraImage() {
Intent chooserIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
File f = new File(Environment.getExternalStorageDirectory(), "POST_IMAGE.jpg");
chooserIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f));
imageToUploadUri = Uri.fromFile(f);
startActivityForResult(chooserIntent, CAMERA_PHOTO);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CAMERA_PHOTO && resultCode == Activity.RESULT_OK) {
if(imageToUploadUri != null){
Uri selectedImage = imageToUploadUri;
getContentResolver().notifyChange(selectedImage, null);
Bitmap reducedSizeBitmap = getBitmap(imageToUploadUri.getPath());
if(reducedSizeBitmap != null){
ImgPhoto.setImageBitmap(reducedSizeBitmap);
Button uploadImageButton = (Button) findViewById(R.id.uploadUserImageButton);
uploadImageButton.setVisibility(View.VISIBLE);
}else{
Toast.makeText(this,"Error while capturing Image",Toast.LENGTH_LONG).show();
}
}else{
Toast.makeText(this,"Error while capturing Image",Toast.LENGTH_LONG).show();
}
}
}
这里是在 onActivityResult() 中使用的 getBitmap() 方法。在获取相机捕获图像位图时，我已经完成了所有可能的性能改进。
private Bitmap getBitmap(String path) {
Uri uri = Uri.fromFile(new File(path));
InputStream in = null;
try {
final int IMAGE_MAX_SIZE = 1200000; // 1.2MP
in = getContentResolver().openInputStream(uri);
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(in, null, o);
in.close();
int scale = 1;
while ((o.outWidth * o.outHeight) * (1 / Math.pow(scale, 2)) >
IMAGE_MAX_SIZE) {
scale++;
}
Log.d("", "scale = " + scale + ", orig-width: " + o.outWidth + ", orig-height: " + o.outHeight);
Bitmap b = null;
in = getContentResolver().openInputStream(uri);
if (scale > 1) {
scale--;
// scale to max possible inSampleSize that still yields an image
// larger than target
o = new BitmapFactory.Options();
o.inSampleSize = scale;
b = BitmapFactory.decodeStream(in, null, o);
// resize to desired dimensions
int height = b.getHeight();
int width = b.getWidth();
Log.d("", "1th scale operation dimenions - width: " + width + ", height: " + height);
double y = Math.sqrt(IMAGE_MAX_SIZE
/ (((double) width) / height));
double x = (y / height) * width;
Bitmap scaledBitmap = Bitmap.createScaledBitmap(b, (int) x,
(int) y, true);
b.recycle();
b = scaledBitmap;
System.gc();
} else {
b = BitmapFactory.decodeStream(in);
}
in.close();
Log.d("", "bitmap size - width: " + b.getWidth() + ", height: " +
b.getHeight());
return b;
} catch (IOException e) {
Log.e("", e.getMessage(), e);
return null;
}
}
希望对您有所帮助！
您面临的问题是，每当我们 select 来自相机意图的图像时，它可能会完成调用它的 activity，因此您创建的 imageUri 对象将是null 而你 return.
所以你需要在退出activity（进入相机意图）时保存它，就像这样-
/**
* Here we store the file url as it will be null after returning from camera
* app
*/
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// save file url in bundle as it will be null on screen orientation
// changes
outState.putParcelable("file_uri", mImageUri);
}
并在您返回 activity -
时将其取回 @Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
// get the file url
mImageUri = savedInstanceState.getParcelable("file_uri");
}
您的代码看起来不错，您只需在其中添加此更改即可。