Android中当前时间的动态显示

//主要使用子线程发送消息 使用Handler更新显示

import java.text.SimpleDateFormat;
import java.util.Date;

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

public class MainActivity extends Activity  implements Runnable{
private Handler handler;
private TextView textView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        textView=(TextView) findViewById(R.id.time);
            handler = new Handler() {
                public void handleMessage(Message msg) {
                    textView.setText((String)msg.obj);
                }
            };
            
        new Thread(this).start();
    }

    @Override
    public void run() {
        // TODO Auto-generated method stub
        try {
            while(true){
                SimpleDateFormat sdf=new SimpleDateFormat("yyyy年MM月dd日   HH:mm:ss");
                String str=sdf.format(new Date());
                handler.sendMessage(handler.obtainMessage(100,str));
                Thread.sleep(1000);
            }
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}