onActivityResult返回data = null

Question

好的,这就是我发送的意图

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
startActivityForResult(intent, REQUEST_CODE);

然后在onActivityResult中我这样做:

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        Log.i("Intent name:",data.toString());
        if (requestCode == REQUEST_CODE){
            if (resultCode == Activity.RESULT_OK){
                Toast.makeText(this, "Image saved to \n" + fileUri.toString() , Toast.LENGTH_LONG).show();
                Toast.makeText(this, "Result Code: " + resultCode , Toast.LENGTH_LONG).show();
                //Bitmap mBitMap = BitmapFactory.decodeFile(data.getData().toString());
                //imageView.setImageBitmap(mBitMap);
            }
            else if (resultCode == RESULT_CANCELED){
                Toast.makeText(this, "Capture Cancelled", Toast.LENGTH_LONG).show();
            }
            else {
                Toast.makeText(this, "Capture failed", Toast.LENGTH_LONG).show();
            }

        }

        super.onActivityResult(requestCode, resultCode, data);
    }  

LogCat在显示Image Saved的行中显示NullPointerException ....
还有:
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=100, result=-1, data=null}

无论我是尝试使用data对象还是fileUri我班级的领域,都会发生这种情况.
为什么要返回数据null？
为什么即使我使用该类的字段我仍然会得到相同的错误？

Answer 1

每当你通过传递带摄像头意图的EXTRAOUTPUT来保存图像时

intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);

在一个文件中,onActivityResultalways 里面的data参数总是返回null.因此,不使用数据来检索图像,而是使用文件路径来检索图像Bitmap.

所以onActivityResult会是这样的:

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (requestCode == REQUEST_CODE) {
        if (resultCode == Activity.RESULT_OK) {
            String[] fileColumn = { MediaStore.Images.Media.DATA };
            Cursor cursor = getContentResolver().query(imageUri,
                fileColumn, null, null, null);
            String contentPath = null;
            if (cursor.moveToFirst()) {
                contentPath = cursor.getString(cursor
                    .getColumnIndex(fileColumn[0]));

                Bitmap bmp = BitmapFactory.decodeFile(contentPath);
                ImageView img = (ImageView) findViewById(R.id.imageView1);
                img.setImageBitmap(bmp);


            } else if (resultCode == RESULT_CANCELED) {
                Toast.makeText(this, "Capture Cancelled", Toast.LENGTH_LONG)
                .show();
            } else {
                Toast.makeText(this, "Capture failed", Toast.LENGTH_LONG)
                .show();
            }

        }

        super.onActivityResult(requestCode, resultCode, data);
    }

确保您已将imageUri或fileUri作为全局变量,以便您也可以在其中访问它onActivityResult.祝你好运