How to start and finish progressBar dynamically in android

Question

When I skip second activity class from first activity class, I will start imageprocessing on certain image in second activity and then until new image comes to screen I wnt

Answer 1

Here is a method which when called starts a progressbar

private void downloadText(String urlStr) {

    final String url = urlStr;
     progressDialog = ProgressDialog.show(this, "", "Trying to register...");
    Log.i("First string", urlStr);
try{
    new Thread () {
        public void run() {
            int BUFFER_SIZE = 2000;
            InputStream in = null;
            try{
           msg = Message.obtain();
            msg.what=1;
            }catch(Exception e)
            {
            }

            try {
                in = openHttpConnection(url);
           InputStreamReader isr = new InputStreamReader(in);
                int charRead;
                  text = "";
                  char[] inputBuffer = new char[BUFFER_SIZE];

                      while ((charRead = isr.read(inputBuffer))>0)
                      {                    
                          //---convert the chars to a String---
                          String readString = 
                          String.copyValueOf(inputBuffer, 0, charRead);                    
                          text += readString;
                          inputBuffer = new char[BUFFER_SIZE];
                      }
                     Bundle b = new Bundle();
                        b.putString("text", text);
                        msg.setData(b);
                      in.close();

            }catch (Exception e) {

            //////////////////////////////////////  
                e.printStackTrace();
            }
            try{
            messageHandler.sendMessage(msg);
            }catch(Exception e)
            {
            }
        }
    }.start();
}catch(Exception e)
{

}

}

and here is the handler code

private Handler messageHandler = new Handler() {


    public void handleMessage(Message msg) {
        try{
        super.handleMessage(msg);
        switch (msg.what) {

        case 1:

{ break; } } progressDialog.dismiss(); }catch(Exception e) {

        }
        }

};