主要講解了主執行緒和子執行緒的handler的訊息傳送：
下面直接上程式碼：

package com.example.handler;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public
 
 class FourActivity extends Activity implements OnClickListener{

    //建立主執行緒的handler
    private Handler handler = new Handler(){
        public void handleMessage(android.os.Message msg) {
            Message message = new Message();
            System.out.println("main Handler");
            //向子執行緒傳送訊息
 

            threadHandler.sendMessageDelayed(message, 1000);
        };
    };


    private Handler threadHandler;
    private Button btn1,btn2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.four);
        btn1 = (Button) findViewById(R.id.button1);
        btn2 = (Button) findViewById(R.id.button2);
        btn1.setOnClickListener(this
 
);
        btn2.setOnClickListener(this);

        HandlerThread thread = new HandlerThread("handlerThread");
        thread.start();
        //建立子執行緒的handler
        threadHandler = new Handler(thread.getLooper()){
            @Override
            public void handleMessage(Message msg) {
                Message message = new Message();
                System.out.println("thread Handler");
                //向主執行緒傳送訊息
                handler.sendMessageDelayed(message, 1000);
            }
        };
    }

    @Override
    public void onClick(View v) {
        switch(v.getId())
        {
        case R.id.button1:
            handler.sendEmptyMessage(1);
        break;
        case R.id.button2:
            handler.removeMessages(1);;
            break;
        }

    }

}