活动中的android Asynctask调用方法

Question

I am downloading a video from a ftp-server via AsyncTask and save it on the device. After the download (onPostExecute) i want to play the video directly in the videoview in my activity, but the problem is can't call my playVideo method since it is not static and instead I have tried to call it in the onResume() method, with the get() method, but the progressbar in my ASynctask doesn't show up then and the app later crashes. Any suggestion?

Thank you in Advance

public class PlayStreamedVideo extends Activity {

final String TAG = "PlayStreamedVideo";
private VideoView videoView;
private MediaController mediaController;
private DownloadVideo download;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.guessvideo);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

    download = new DownloadVideo(PlayStreamedVideo.this, SAVE_PATH);
    download.execute();

}
    @Override
    protected void onResume(){
        try {
            while(download.get() == false){
                Log.d(TAG, "1");
            }
            playVideo();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ExecutionException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        super.onResume();   
    }

public void playVideo() {
    try {
        videoView = (VideoView) findViewById(R.id.streamedVideoSurface);
        mediaController = new MediaController(this);
        videoView.setVideoURI(Uri.parse(SAVE_PATH));
        videoView.setMediaController(mediaController);
        videoView.start();
    } catch (Exception e) {
        // Log.e(TAG, "error: " + e.getMessage(), e);
    }
}

Answer 1

In my opinion you should't call that function in the onResume method. You could pass to the asynctask a pointer to your activity and then call your play function on post-execute:

download = new DownloadVideo(PlayStreamedVideoActivity, SAVE_PATH);

What are you passing as first parameter is the context and not the instance rappresenting your activity.

Then call the function into the onPostExecute like this:

PlayStreamedVideoActivity.playVideo();

Remember to modify your asynctask constructor acoordingly.

Answer 2

I think it is easier to declare videoView as a member of PlayStreamedVideo class. Put the declarations to onCreate():

    videoView = (VideoView) findViewById(R.id.streamedVideoSurface);
    mediaController = new MediaController(this);
    videoView.setMediaController(mediaController);

Then just call from onPostExecute():

    videoView.setVideoURI(Uri.parse(SAVE_PATH));
    videoView.start();