Javatech

There are 3 important methods to override in AsyncTask.

1. doInBackground : this is where the meat of your background processing will occur.
2. onPreExecute : show your ProgressDialog here ( showDialog )
3. onPostExecute : hide your ProgressDialog here ( removeDialog or dismissDialog )

If you make your AsyncTask subclass as an inner class of your activity, then you can call the framework methods showDialog, dismissDialog, and removeDialog from within your AsyncActivity.

Here’s a sample implementation of AsyncTask:

class LoginProgressTask extends AsyncTask {
    @Override
    protected Boolean doInBackground(String... params) {
        try {
            Thread.sleep(4000);  // Do your real work here
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return Boolean.TRUE;   // Return your real result here
    }

    @Override
    protected void onPreExecute() {
        showDialog(AUTHORIZING_DIALOG);
    }

    @Override
    protected void onPostExecute(Boolean result) {
        // result is the value returned from doInBackground
        removeDialog(AUTHORIZING_DIALOG);
        Intent i = new Intent(HelloAndroid.this, LandingActivity.class);
        startActivity(i);
    }
}

I was putting some Video into an Android application for the first time. I was hoping this wouldn’t be too difficult and was delighted to find the VideoView component. It was really simple to add a VideoView to my layout:

<VideoView android:layout_height="wrap_content"
		android:layout_width="wrap_content"
		android:id="@+id/videoView"/>

Then I prepared the video and added it to my project as follows:
1) Convert your video to either gp3, mp4 or wmv format. (Yeah, wmv works surprisingly. avi and flv do not work ).
2) Copy the video into your project’s res/raw folder. For example’s sake, I’ll say the video I copied there is named “my_video.mp4”
** Android will detect this and create a static resource ID for you named R.raw.my_video – you will use this (and not the file name) when building the URI to play your video.
3) Add code in my Activity that would lookup the VideoView, set the URI and start the player:

        VideoView vv = (VideoView)this.findViewById(R.id.videoView);
        String fileName = "android.resource://" + getPackageName() + "/" + R.raw.my_video;
        vv.setVideoURI(Uri.parse(fileName));
        vv.start();

There you have it…

I was so excited to get the new ADT installed and try out all of it’s new features that I was updating the ADT through eclipse and the SDK through the SDK Manager. The SDK Manager threw up this message box:
On windows this typically means that a program is using that folder…Please momentarily deactivate your anti-virus software.
Well, this was the most awesome error message I’d ever gotten. So, I went to my task manager to look for some unknown background anti-virus that may have come pre-installed on my system. I didn’t find anything, but closed a couple seemingly extraneous tasks. Closing these tasks did not help. But I was able to click YES and try again. And again.
Please also close any running programs that may be accessing the directory ..\platform-tools.
Long story short, it was Eclipse’s ADT that had a handle on the platform-tools directory. Closing Eclipse allowed the SDK manager to continue with its update This friendly error message dialog that let me troubleshoot the problem and click YES until I got it saved me a lot of time and headache. Thanks for the nice update installer logic!