package com.example.demo_test;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.Menu;import android.widget.TextView;public class MainActivity extends Activity {    private TextView tvShow;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        tvShow = (TextView) findViewById(R.id.tv_show);        new Thread(new ThreadChangeUI(handler)).start();    }    // handler类接收数据    Handler handler = new Handler() {        public void handleMessage(Message msg) {            if (msg.what == 1) {                // 动态更新UI界面                String str = msg.getData().getInt("num") + "";                System.out.println("str----------------->" + str);                tvShow.setText(str);            }        };    };    @Override    public boolean onCreateOptionsMenu(Menu menu) {        getMenuInflater().inflate(R.menu.activity_main, menu);        return true;    }}

线程:

package com.example.demo_test;import android.os.Bundle;import android.os.Handler;import android.os.Message;public class ThreadChangeUI implements Runnable {    private Handler handler;    private int num = 0;    public ThreadChangeUI(Handler handler) {        // TODO Auto-generated constructor stub        this.handler = handler;    }    @Override    public void run() {        // 每秒改变textview的值        while (true) {            try {                Thread.sleep(1000);                Message msg = new Message();                msg.what = 1;                // handler传递参数                // handler.sendMessage(msg);                Bundle bundle = new Bundle();                bundle.putInt("num", num++);                System.out.println("num---------->" + num);                msg.setData(bundle);                handler.sendMessage(msg);            } catch (Exception e) {                // TODO Auto-generated catch block                e.printStackTrace();                System.out.println("thread error...");            }        }    }}