Handler kullanarak Thread içinden UI bileşenine mesaj işlemek

Ref: http://www.helloandroid.com/tutorials/using-threads-and-progressdialog

    public class ProgressDialogExample extends Activity implements Runnable {
     
            private String pi_string;
            private TextView tv;
            private ProgressDialog pd;
     
            @Override
            public void onCreate(Bundle icicle) {
                    super.onCreate(icicle);
                    setContentView(R.layout.main);
     
                    tv = (TextView) this.findViewById(R.id.main);
                    tv.setText("Press any key to start calculation");
            }
     
            @Override
            public boolean onKeyDown(int keyCode, KeyEvent event) {
     
                    pd = ProgressDialog.show(this, "Working..", "Calculating Pi", true,
                                    false);
     
                    Thread thread = new Thread(this);
                    thread.start();
     
                    return super.onKeyDown(keyCode, event);
            }
     
            public void run() {
                    pi_string = Pi.computePi(800).toString();
                    handler.sendEmptyMessage(0);
            }
     
            private Handler handler = new Handler() {
                    @Override
                    public void handleMessage(Message msg) {
                            pd.dismiss();
                            tv.setText(pi_string);
     
                    }
            };     
    }