java摄像头应用程序在按下后退按钮时保存空文件
我正在片段中使用一个摄像头应用程序。一切正常,拍摄的照片保存在我希望的地方
问题是,当我在照片应用程序中按下设备上的后退按钮时,会保存一张空图像。我怎样才能避免呢
这是我的CameraActivity
:
public class CameraActivity extends Activity {
private static final String TAG = "CameraActivity";
String currentFilePath;
String currentFileName;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
new CameraTask().execute();
}
public void dispatchPictureIntent() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
File photoFile = null;
try {
photoFile = createImageFile();
} catch (IOException e) {
Toast.makeText(this, R.string.msg_picture_not_saved, Toast.LENGTH_LONG).show();
}
if (photoFile != null) {
Uri photoUri = FileProvider.getUriForFile(this, getClass().getCanonicalName(), photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoUri);
startActivityForResult(takePictureIntent, Constants.REQUEST_TO_TAKE_PICTURE);
addPictureToGallery();
dispatchDataIntent();
}
}
}
public File createImageFile() throws IOException {
File pathOfStorageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM + "/Camera");
pathOfStorageDir.mkdir();
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String filePrefix = "img_" + timeStamp + "_";
String suffix = ".jpg";
File image = File.createTempFile(filePrefix, suffix, pathOfStorageDir);
currentFileName = image.getName();
currentFilePath = image.getAbsolutePath();
return image;
}
private void addPictureToGallery() {
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
File f = new File(currentFilePath);
Uri contentUri = Uri.fromFile(f);
mediaScanIntent.setData(contentUri);
this.sendBroadcast(mediaScanIntent);
}
private void dispatchDataIntent() {
Intent data = new Intent();
data.putExtra(Constants.IMAGE_FILE_NAME, currentFileName);
setResult(CameraActivity.RESULT_OK, data);
}
private class CameraTask extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... params) {
dispatchPictureIntent();
return null;
}
@Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
finish();
}
}
}
谢谢你的帮助
# 1 楼答案
您的代码始终保存图像文件。如果用户按下后退按钮,尝试删除保存的图片。更好的方法是在检查结果代码之后将图像保存在
onActivityResult