Question

我正在开发一个图像编辑Android应用程序。在我的一个活动中，我打算从onCreate中的画廊中选择一个图像：

Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);

然后我收到这样的数据：

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    Crashlytics.log("onActivityResult called");
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == PICK_IMAGE && resultCode == Activity.RESULT_OK && data != null) {
        Crashlytics.log("Data received from image pick intent");
        imageUri = data.getData();
        loadImage();
    } else {
        //if we do not select a picture, go back to the dashboard
        Crashlytics.log("Data not received");
        onBackPressed();
        Log.d(TAG, "no picture selected");
    }
}

loadImage方法：

private void loadImage() {
    try {
        photoBitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), imageUri);
    } catch (IOException e) {
        Crashlytics.log("IOException from getBitmap");
        Log.d(TAG, e.getMessage());
        showToastAndPressBack();
        return;
    }

    if (photoBitmap == null) {
        Crashlytics.log("photoBitmap is null in onActivityResult");
        showToastAndPressBack();
        return;
    }

    Display display = getWindowManager().getDefaultDisplay();
    Point size = new Point();
    display.getSize(size);
    imgVWidth = size.x;
    int height = size.y;
    imgVHeight = (int) (((float) imgVWidth / photoBitmap.getWidth()) * photoBitmap.getHeight());
    photoInImgViewBitmap = Bitmap.createScaledBitmap(photoBitmap, imgVWidth, imgVHeight, true);
    imageAlreadyPicked = true;
}

现在我的问题是，有时我看到Crashlytics中的NPE-s声称当用户按下下一个按钮时，photoBitmap为空。

@OnClick(R.id.toolbar_next)
void onToolbarNextClick() {
    float originalScale = (float) (previewImageView.getHeight()) / (float) (photoBitmap.getHeight());
    ...
}

我看到的唯一一个Crashlytics日志是用户离开了意图（我在onPause内放置了一个Crashlytics日志）。没有onActivityResult的日志，所以我最好的猜测是onActivityResult没有被调用，因此我的位图没有加载，因此当用户按下它时它将为null。

问题：为什么有时会调用onActivityResult，有时不会？是否有photoBitmap为空的其他可能原因？

Answer 1

您必须添加以下代码才能从设备中获取图像

"react-native-localize": "^2.0.1",
"react-native": "~0.63.4",

Answer 2

要开始相机活动，请使用此代码

   Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
            startActivityForResult(cameraIntent, CAMERA_REQUEST);

获取位图

 @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(resultCode == Activity.RESULT_OK){
        if(requestCode==CAMERA_REQUEST) {
            Bitmap photo = (Bitmap) data.getExtras().get("data"); }
         }else{
           //Camera request cancelled}
        }

Answer 3

试试这个工作完美

     Intent i = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(i, LOAD_IMAGE_RESULTS);

  @SuppressLint("Recycle")
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

           if (requestCode == LOAD_IMAGE_RESULTS && resultCode == RESULT_OK && data != null) {
                    // Let's read picked image data - its URI
                    Uri pickedImage = data.getData();

                    // Let's read picked image path using content resolver
                    String[] filePath = {MediaStore.Images.Media.DATA};
                    @SuppressLint("Recycle") Cursor cursor = null;
                    if (pickedImage != null) {
                        cursor = getContentResolver().query(pickedImage, filePath, null, null, null);
                    }
                    if (cursor != null) {
                        cursor.moveToFirst();

                        String imagePath = cursor.getString(cursor.getColumnIndex(filePath[0]));
      }
    }
}

现在您可以将imagepath转换为位图

Answer 4

使用此选项从图库中选择：

Intent i = new Intent(Intent.ACTION_PICK);
i.setType("image/*");
startActivityForResult(i, REQUEST_CODE);

现在你将在onActivityResult中获得一个回调：

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch (requestCode) {
        case REQUEST_CODE:
            if (resultCode != RESULT_CANCELED) {
//use data to get the selected image
            }
            break;
    }
}

Answer 5

在代码最后一行方法后调用super.onActivityResult。当你给超级电话打电话时，你告诉安卓你完成了。

我还注意到你记录了一个char序列。不要这样做你不会用这个解决任何问题。

 Crashlytics.log("Data not received");

您需要保存一些数据。认为用户已取消，因为您的代码无法捕获此内容。

/ *假设log方法有一个int输入* /

Crashlytics.log("Data not received");
Crashlytics.log(requestCode);
Crashlytics.log(resultCode);

在ACTION_GET_CONTENT意图

5 个答案: