我正在尝试使用Intent. 我正在启动startActivityForResult，相机应用程序启动。拍完照片后，我按下保存按钮并尝试退回我的申请。但在onActivityResult Intent data总是null。我的应用基于 Android 开发者相机教程。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
}
}
}