Question

I have a button that onclick reads and shows to the user a list with rss news. I would like to add a progress bar until finish loading. My problem is that, if I add a bar, it works properly at first but if I press the back button, the bar starts again and it can’t stop. Any help or a tutorial that demonstrates a progressbar would be appreciated. Thanks!

ProgressBar myProgressBar;
  int myProgress = 0;

 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle icicle) {
  super.onCreate(icicle);
  setContentView(R.layout.main1);

  Button nea = (Button) findViewById(R.id.nea);
   nea.setOnClickListener(new View.OnClickListener() {
   public void onClick (View view) {
    setContentView(R.layout.bar);

     myProgressBar=(ProgressBar)findViewById(R.id.bar);

           new Thread(myThread).start();

    Intent myIntent = new Intent(view.getContext(), nea.class);
    startActivityForResult(myIntent, 0);
    }  
  });
}

private Runnable myThread = new Runnable(){    
    @Override
    public void run() {
     // TODO Auto-generated method stub
     while (myProgress<100){
      try{
       myHandle.sendMessage(myHandle.obtainMessage());
       Thread.sleep(1000);
      }
      catch(Throwable t){
      }
     }
    }

    Handler myHandle = new Handler(){

     public void handleMessage(Message msg) {
      // TODO Auto-generated method stub
      myProgress++;
      myProgressBar.setProgress(myProgress);
     }
    };
      };

Answer 1

Actually I’d implement this with an AsyncTask, where you start the progress bar in onPreExecute(), cancel it in onPostExecute() and do the downloading in doInBackground(). If you want to update the progress value, you can publishProgress() from doInBackground() which can then be updated on the ProgressBar in onProgressUpdate()

https://github.com/pilhuhn/ZwitscherA/blob/master/src/de/bsd/zwitscher/TweetListActivity.java#L328
shows how an example of an AsyncTask that uses those methods and which shows / hides a progress bar ( pg variable )