Android&MyThread

package com.zachary.activitythread;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.KeyEvent;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {

    Handler hd= new Handler(){

        @Override
        public void handleMessage(Message msg) {
            // TODO Auto-generated method stub
            switch(msg.what){
                case 1:
                    Bundle b = msg.getData();
                    String str = b.getString("msg");
                    myTextView.setText(str);
                    break;
            }
        }
        
    };
    private TextView myTextView = null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        myTextView = (TextView)findViewById(R.id.myTextView);
        System.out.println("Activity----->"+Thread.currentThread().getId());
        new MyThread(MainActivity.this).start();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        if(keyCode==4)
            System.exit(0);
        return super.onKeyDown(keyCode, event);
    }

}

package com.zachary.activitythread;

import android.os.Bundle;
import android.os.Message;

public class MyThread extends Thread{

    int count = 0;
    MainActivity activity;
    boolean flag = true;
    public MyThread(MainActivity activity){
        this.activity = activity;
    }
    @Override
    public void run() {
        // TODO Auto-generated method stub
        while(flag){
            if(count>=10)
                flag = false;
            String msg = "第" + ++count +"次更改TextView";
            Bundle bd = new Bundle();
            bd.putString("msg", msg);
            Message tempMessage = new Message();
            tempMessage.setData(bd);
            tempMessage.what = 1;
            activity.hd.sendMessage(tempMessage);
            System.out.println("MyThread----->" + Thread.currentThread().getId());
            try {
                sleep(1000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        super.run();
    }
    
}