case R.id.btn_stop:
    handler.removeMessages(0);
    handler2.removeMessages(0);
    break;

同时写两个就管用.  我试了这个可以停止.

public class MainActivity extends Activity implements OnClickListener{

private HandlerThread thread;

private TextView text;

private Button send;

private Button stop;

//创建主线程的Handler

private Handler mainHandler=new Handler(){

public void handleMessage(android.os.Message msg) {

//往子线程中发送消息

threadHandler.sendEmptyMessageDelayed(1,1000);

Log.e("TAG","in Main Thread"+Thread.currentThread());

};

};

private Handler threadHandler;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

text=(TextView) findViewById(R.id.textView1);

send=(Button) findViewById(R.id.send);

stop=(Button) findViewById(R.id.stop);

send.setOnClickListener(this);

stop.setOnClickListener(this);

thread= new HandlerThread("Handler Thread");

thread.start();

threadHandler=new Handler(thread.getLooper()){

@Override

public void handleMessage(Message msg) {

Log.d("TAG","in new Thread"+Thread.currentThread());

//往主线程发送消息

mainHandler.sendEmptyMessageDelayed(1,1000);

// super.handleMessage(msg);

}

};

}