Android Handler传递参数动态更新UI界面demo

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 == ) {
                // 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 = ;
 
    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();
                Message msg = new Message();
                msg.what = ;
                // 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...");
            }
        }
    }
 
}