Question

我正在尝试使用Intent拍照。我正在启动startActivityForResult并启动相机应用程序。拍照后，我按下保存按钮，试图返回我的应用程序。但在onActivityResult Intent data始终是null。我的应用程序基于Android Developer相机教程。这是我的代码：

public class MainActivity extends Activity {
    private static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100;
    private static final int MEDIA_TYPE_IMAGE = 1;
    private static Intent intent;
    private TextView tv;

    private Uri fileUri;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout_main);

        // create Intent to take a picture and return control to the calling
        // application
        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

        Button b = (Button)findViewById(R.id.button1);
        b.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
            }
        });

        tv = (TextView)findViewById(R.id.textView1);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    /** 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) {
        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();
            if(data != null)
                tv.setText("Dosya şuraya kaydedildi:\n" + data.getData());
        } else if (resultCode == RESULT_CANCELED) {
            // User cancelled the image capture
        } else {
            // Image capture failed, advise user
        }
    }
}

Answer 1

我在这个问题中找到了答案：
android camera: onActivityResult() intent is null if it had extras
“如果你没有指定MediaStore.EXTRA_OUTPUT，那么你将有一个意图，其中包含相机保存照片的文件中的uri。”

startActivityForResult拍照并保存，但Intent为null

1 个答案: