How to properly implement android.os.Handler class instead of Timer in Android application?

So I wanted to implement Timer in my Anroid program and I found out the better way to do that is using Handler class.

First I decided to write the simplest program using Handler - the text is set after 1 second. I'm totall beginner in Android, so I went through some tutorials on web especially that one http://developer.android.com/resources/articles/timed-ui-updates.html , but still my application shows error ("application mTimer stopped").

So could anyone point out where exactly am I making mistake? I would be gratefull, here's the code:

public class mTimer extends Activity {

    TextView tv;
    Button button1,button2;
    Handler mHandler;

    private Runnable myTask = new Runnable() {
           public void run() {

               tv.setText("text");

           }
        };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        button1=(Button)findViewById(R.id.button1);
        tv=(TextView)findViewById(R.id.textView1);

 b开发者_如何学编程utton1.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                mHandler.postDelayed(myTask, 100);
            }
        });


    }
}

You should initialize your Handler in your onCreate method with at least a code like mHandler = new Handler();.

Note, that the myTask task will be run on the UI thread, since your handler is declared there

API Docs for Handler.postDelayed:

The runnable will be run on the thread to which this handler is attached.