当时遇到的主要难点在于TextView的内容不会刷新改变值，今天终于通过Timer和Handler实现了，分享给大家

import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class AndroidLuckyActivity extends Activity
{
        private TextView textView;
        private Button button_start;
        private Button button_end;
        private Boolean begined = false;
        private Timer timer;
        private Handler handler;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        init();
        handler = new Handler()
        {
 public void handleMessage(Message msg)
                {
                        super.handleMessage(msg);
                        if(begined == true)
                        {
                                textView.setText("" +msg.what);
                        }
                        else if(begined == false)
                        {
　　　　　　　　　　　　　　　　　　　 textView.setText("" + msg.what);
                                timer.cancel();                        //Timer停止
                        }
                }
        };
    }

    void init()
    {
            textView = (TextView)this.findViewById(R.id.tv);
            button_start = (Button)this.findViewById(R.id.btn_start);
            button_end = (Button)this.findViewById(R.id.btn_end);
        button_start.setOnClickListener(new Button.OnClickListener()
        {
                        @Override
                        public void onClick(View v)
                        {
                                // TODO Auto-generated method stub
                                begined = true;
                                button_start.setEnabled(false);
                                button_end.setEnabled(true);
                                timer = new Timer();
                                timer.schedule(new TimerTask() 
                                {
                                        @Override
                                        public void run()
                                        {
                                                // TODO Auto-generated method stub
                                                Message message = new Message();
                                                message.what = (int) (Math.random() * 999 + 100);
                                                handler.sendMessage(message);
                                        }
                                }, 1000, 30);        //从1000ms即1s开始，30ms为数字改变周期
                        }
        });
        button_end.setOnClickListener(new Button.OnClickListener()
        {
                        @Override
                        public void onClick(View v)
                        {
                                // TODO Auto-generated method stub
                                begined = false;
                                button_start.setEnabled(true);
                                button_end.setEnabled(false);
                        }
        });
    }
}

运行图：