android秒表代码的注释速求

package com.example.yk;


import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class CreativeActivity extends Activity {

    private TextView minText;       //分
    private TextView secText;       //秒
    private Button start;           //开始按钮
    private Button stop;            //停止按钮
    private boolean isPaused = false;
    private String timeUsed;
    private int timeUsedInsec;

    private Handler uiHandle = new Handler(){
        public void handleMessage(android.os.Message msg) {
            switch(msg.what){
            case 1:
                if(!isPaused) {
                    addTimeUsed();//添加
                    updateClockUI();//更新
                }
                uiHandle.sendEmptyMessageDelayed(1, 1000);//
                break;
            default: break;
            }
        }
    };


    @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_creative);

       //获取界面的控件
       minText = (TextView) findViewById(R.id.min);
       secText = (TextView) findViewById(R.id.sec);
       start = (Button) findViewById(R.id.start);
       stop = (Button) findViewById(R.id.stop);


       //为按钮Start注册监听器
       start.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                uiHandle.removeMessages(1);
                startTime();
                isPaused = false;
            }
        });

       //为按钮stop注册监听器
       stop.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                isPaused = true;
                timeUsedInsec = 0;
            }
        });
   }   


   @Override
   protected void onPause() {
    // TODO Auto-generated method stub
    super.onPause();
    isPaused = true;
   }


   @Override
   protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    isPaused = false;
   }

   private void startTime(){
    uiHandle.sendEmptyMessageDelayed(1, 1000);
   }

   /**
    * 更新时间的显示
    */
   private void updateClockUI(){
    minText.setText(getMin() + ":");
    secText.setText(getSec());
   }

   public void addTimeUsed(){
    timeUsedInsec = timeUsedInsec + 1;
    timeUsed = this.getMin() + ":" + this.getSec();
   }

   public CharSequence getMin(){
    return String.valueOf(timeUsedInsec / 60);
   }

   public CharSequence getSec(){
    int sec = timeUsedInsec % 60;
    return sec < 10? "0" + sec :String.valueOf(sec);
   }

   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
       getMenuInflater().inflate(R.menu.creative, menu);
       return true;
   }


}