Android：使用 ActivityResultLauncher 时如何区分多个意图

Question

我正在创建一个意图选择器，以在手机相机应用程序和图库/文件管理器之间进行选择。

Intent chooserIntent = Intent.createChooser(clickPhoto(),"Set Image Using");
                        chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS,openGallery());
                        startActivityForResult.launch(chooserIntent);

点击拍照方式：

private Intent clickPhoto() {
        Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        ComponentName componentName = takePictureIntent.resolveActivity(requireActivity().getPackageManager());
        if (componentName != null) {
            try {
                createImageFile();
                mimeType = "image/*";
                ContentValues values = new ContentValues();
                values.put(MediaStore.Images.Media.DISPLAY_NAME, getNewFileName());
                values.put(MediaStore.Images.Media.MIME_TYPE, mimeType);
                values.put(MediaStore.Images.Media.RELATIVE_PATH, getImageDirectoryPath());

                Uri imageUri = requireActivity().getContentResolver().insert(MediaStore.Images.Media.getContentUri(MediaStore.VOLUME_EXTERNAL), values);
                if (imageUri != null) {
                    currentPhotoPath = imageUri.toString();
                    shareUri = imageUri;
                }
                takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);

               // initRequestCode(takePictureIntent, requestCode);
            } catch (IOException ioException) {
                Toast.makeText(requireContext(), ioException.getMessage().toString(), Toast.LENGTH_LONG).show();

            }

        }
        return takePictureIntent;
    }

打开画廊方法：

private Intent openGallery(){
    mimeType = "image/*";
    Intent intent = new Intent();
    Uri collection = MediaStore.Video.Media.getContentUri(
            MediaStore.VOLUME_EXTERNAL);

    try {
         intent =
                new Intent(Intent.ACTION_PICK, collection).setType(mimeType);
        intent.resolveActivity(requireActivity().getPackageManager());

       // initRequestCode(intent, requestCode);
    } catch (ActivityNotFoundException e) {
        Toast.makeText(requireContext(), e.getLocalizedMessage(), Toast.LENGTH_LONG).show();
    }
    return intent;
}

ActivityResultLauncher：

ActivityResultLauncher<Intent> startActivityForResult = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(),
            result -> {
                if (result.getResultCode() == Activity.RESULT_OK) {
                   //how to tell which intent the user selected ?
                }
            });

我如何知道用户是使用相机拍照还是使用文件选择器拾取图像？

Answer 1

你可以这样区分，

如果一种方法是针对相机意图，

 private fun openCamera() { val takePictureIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE) if (takePictureIntent.resolveActivity(packageManager) != null) { cameraImageFile = getTempFile() cameraImageFile?.let { val imageUri = FileProvider.getUriForFile( this, "${BuildConfig.APPLICATION_ID}.fileprovider", it ) cameraLauncher.launch(imageUri) } } }

另一种方法是画廊意图

 private fun openGallery() { galleryLauncher.launch("image/*") }

然后你可以在活动中定义它们，如下所示，

 //Todo for gallery private val galleryLauncher = registerForActivityResult(ActivityResultContracts.GetContent()) { //code here for gallery } //Todo for camera private val cameraLauncher = registerForActivityResult(ActivityResultContracts.TakePicture()) { //code here for camera }

而已！

Answer 2

声明一些变量

companion object{
    private const val CAMERA_ACTION =1
    private const val GALLERY_ACTION =2
    private const val CHOOSER_INTENT_ACTION =3
}
private var mActionTriggered =0

然后跟随

private fun openCamera() {
    mActionTriggered = CAMERA_ACTION
}

private fun openGallery() {
    mActionTriggered =GALLERY_ACTION
}

private fun openChooser() {
    mActionTriggered =CHOOSER_INTENT_ACTION
}

onResult

private val startActivityForResult = registerForActivityResult(
    StartActivityForResult()
) { result: ActivityResult ->
    if (result.resultCode == RESULT_OK) {
        when (mActionTriggered) {
            CAMERA_ACTION -> {
                mActionTriggered =  0
                //TODO your logics
            }
            GALLERY_ACTION -> {
                mActionTriggered =   0
                //TODO your logics
            }
            else -> {
                mActionTriggered =   0
                //TODO your logics
            }
        }
    }else{
        mActionTriggered =  0
    }
}

Answer 3

感觉有点矫枉过正，不过可以使用选择器活动的细化机制。

您需要自己实现细化活动，但您可以使用选择器传递的EXTRA_RESULT_RECEIVER来发回结果。

Intent refinementIntent = new Intent(this, RefinementActivity.class);
PendingIntent refinementPendingIntent = PendingIntent.getActivity(this, 0, refinementIntent, 0);
Intent clickPhotoIntent = clickPhoto();
Intent chooserIntent = Intent.createChooser(clickPhoto(),"Set Image Using");
chooserIntent.putExtra(
    Intent.EXTRA_CHOOSER_REFINEMENT_INTENT_SENDER, refinementPendingIntent.getIntentSender());
chooserIntent.putExtra(Intent.EXTRA_RESULT_RECEIVER, new ResultReceiver() {
  @Override
  public void onReceive(int resultCode, Bundle resultData) {
    Intent startedIntent = resultData.getParcelable("extra_selected_intent");
    // Check which intent was selected.
    // Note that this is called when the selection happened, before the
    // started activity returned. Probably what you want to do here is
    // cache the value in a field and then check it when you get
    // the activity result.
  }
});
chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, openGallery());
startActivityForResult.launch(chooserIntent);

然后在RefinementActivity.java中，您需要将选定的意图发送回发送者

@Override
public void onCreate(Bundle savedInstanceState) { 
  Intent selectedIntent = getIntent().getParcelableExtra(Intent.EXTRA_INTENT);
  ResultReceiver receiver = getIntent().getParcelableExtra(Intent.EXTRA_RESULT_RECEIVER);
  Bundle resultData = new Bundle();
  resultData.putParcelable("extra_selected_intent", selectedIntent);
  receiver.send(RESULT_OK, resultData);

  startActivity(selectedIntent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT));
  finish();
}

Answer 4

您可以在返回它们之前为每个意图添加一个额外的整数，您可以在结果中访问它们，例如：

全局变量

   final String SOURCE = "source";
    final int SOURCE_CAMERA = 0;
    final int SOURCE_GALLERY = 1;
   final int SOURCE_UNKNOWN = 2;

相机用

...
takePictureIntent.putExtra(SOURCE, SOURCE_CAMERA);
return takePictureIntent;

画廊

..
intent.putExtra(SOURCE, SOURCE_GALLERY);
return intent;

活动结果启动器

if (result.getResultCode() == Activity.RESULT_OK) {
        //Identify source
       int mySource = result.getData().getIntExtra(SOURCE, SOURCE_UNKNOWN )         
}

Answer 5

您可以初始化全局布尔值名称 isGallery 并在 openGallery() 中将其设置为 true，在clickPhoto()中将其设置为 false

就像下面的代码：

private  boolean isGallery ;

private Intent clickPhoto() {
    isGallery = false;
}

private Intent openGallery() {
    isGallery = true;
}

现在您的ActivityResultLauncher将是这样的：

ActivityResultLauncher<Intent> startActivityForResult =
 registerForActivityResult(new ActivityResultContracts.StartActivityForResult(),
            result -> {
                if (result.getResultCode() == Activity.RESULT_OK) {
                    if (isGallery) {
                        // user picked an image with the file picker
                    } else {
                        // user took a picture using the camera
                    }

                }
            });