Android - using runOnUiThread to do UI changes from a thread

Question

I am using a custom title view and would like to show/hide a progressbar in the title view when a thread is working.

This is my title view\'s XML

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Answer 1

Few Things to try:

1) (This probably isn't it) Make sure "titleProgress" is volatile.

2) Try throwing a few postInvalidate() or titleProgress.postInvalidate() in there to trigger a redraw.

3) Have you sacraficed a x486 machine on an alter resembling a giant green robot? (just kidding)

Let me know if those first two (and if you're really desperate, the third) get you anywhere.

Answer 2

use Communication with Handlers ,

1. execute your thread
2. into run() : you should send a message to the Handler which will update the progressBar (Horizontal of course ) : handler.sendMessage(handler.obtainMessage());

3. in your Activity , you should override the method handleMessage(Message msg ) : like this

   handler = new Handler(){
     @override
     public void handleMessage(Message msg ) 
     {
       //here you write the code which will update your progressBar 
     }
   };
   

Answer 3

Is your layout correct? Did you try to get this working with a vertical layout first? Just to see if the progress bar is visible when you start your activity?

Answer 4

What you should use in this case is AsyncTask, see http://developer.android.com/reference/android/os/AsyncTask.html

If you're not targeting a pre-1.5 version of Android, you will have to use a different class called UserTask. See http://android-developers.blogspot.com/2009/05/painless-threading.html

Answer 5

Try changing the style of the ProgressBar to horizonal:

style="?android:attr/progressBarStyleHorizontal"

The original

style="?android:attr/progressBarStyleSmall"

gives a circular "progressbar" which can't be fully seen in the titlebar.