Progress bar

The following code example shows how a progress bar can be used from a worker thread to update the user interface to notify the user of progress:

 public class MyActivity extends Activity {
     private static final int PROGRESS = 0x1;

     private ProgressBar mProgress;
     private int mProgressStatus = 0;

     private Handler mHandler = new Handler();

     protected void onCreate(Bundle icicle) {
         super.onCreate(icicle);

         setContentView(R.layout.progressbar_activity);

         mProgress = (ProgressBar) findViewById(R.id.progress_bar);

         // Start lengthy operation in a background thread
         new Thread(new Runnable() {
             public void run() {
                 while (mProgressStatus < 100) {
                     mProgressStatus = doWork();

                     // Update the progress bar
                     mHandler.post(new Runnable() {
                         public void run() {
                             mProgress.setProgress(mProgressStatus);
                         }
                     });
                 }
             }
         }).start();
     }
 }
To add a progress bar to a layout file, you can use the <ProgressBar> element. By default, the progress bar is a spinning wheel (an indeterminate indicator). To change to a horizontal progress bar, apply the Widget.ProgressBar.Horizontal style, like so:

<ProgressBar
     style="@android:style/Widget.ProgressBar.Horizontal"
     ... />