android - 未能将 Intent 结果传递回 Activity ，android 图像捕获 Intent

Question

我正在尝试在我的 Android 应用程序中实现一个简单的图像捕获，并返回保存图像的路径。我正在关注 android 文档中的示例，但是当我捕获图像并按“保存”时，我的应用程序崩溃并出现以下异常:

Failure delivering result ResultInfo{who=null, request=100, result=-1, data=null} to activity {com.fideli/com.fideli.MainActivity}: java.lang.NullPointerException

为什么数据=空？？我试图寻找修复方法，但没有一个有帮助。有人可以帮我提出建议吗？

谢谢!

主要 Activity :

  private void takePicture() {
        // create Intent to take a picture and return control to the calling application
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

        fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); // create a file to save the image
        intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file name

        // start the image capture Intent
        startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);

    }


    /** Create a file Uri for saving an image or video */
    private static Uri getOutputMediaFileUri(int type){
          return Uri.fromFile(getOutputMediaFile(type));
    }

    /** Create a File for saving an image or video */
    private static File getOutputMediaFile(int type){
        // To be safe, you should check that the SDCard is mounted
        // using Environment.getExternalStorageState() before doing this.

        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
                  Environment.DIRECTORY_PICTURES), "MyCameraApp");
        // This location works best if you want the created images to be shared
        // between applications and persist after your app has been uninstalled.

        // Create the storage directory if it does not exist
        if (! mediaStorageDir.exists()){
            if (! mediaStorageDir.mkdirs()){
                Log.d("MyCameraApp", "failed to create directory");
                return null;
            }
        }

        // Create a media file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        File mediaFile;
        if (type == 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) {
        //Bundle bundle = data.getExtras();
        //Log.i("TAG", "Image saved to:\n" + bundle);
        if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) {
            if (resultCode == RESULT_OK) {
                // Image captured and saved to fileUri specified in the Intent
               // Toast.makeText(this, "Image saved to:\n" + data.getData(), Toast.LENGTH_LONG).show();
                Log.i("TAG", "Image saved to:\n" + data.getData());
            } else if (resultCode == RESULT_CANCELED) {
                // User cancelled the image capture
            } else {
                // Image capture failed, advise user
            }
            }
        }

Answer 1

图像被写入您在 Intent extra MediaStore.ACTION_IMAGE_CAPTURE.EXTRA_OUTPUT 中传递的 Uri。在 onActivityResult() 中传递回您的 Activity 的 Intent 不包含图像，也不包含 data 中的 Uri Intent 的字段。在 onActivityResult() 中，您可以从调用 getOutputMediaFileUri(int type) 时返回的文件中获取图像。