Android计时器控件Chronometer应用实例

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" 
 xmlns:tools="http://schemas.android.com/tools" 
 android:id="@+id/linearlayout1" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 android:orientation="horizontal" 
 android:paddingbottom="@dimen/activity_vertical_margin" 
 android:paddingleft="@dimen/activity_horizontal_margin" 
 android:paddingright="@dimen/activity_horizontal_margin" 
 android:paddingtop="@dimen/activity_vertical_margin" 
 tools:context=".mainactivity" 
 android:background="@drawable/bg" > 
 
 <chronometer 
  android:id="@+id/chronometer" 
  android:layout_margintop="8dp" 
  android:layout_marginleft="5dp" 
  android:layout_width="wrap_content" 
  android:layout_height="wrap_content" /> 
 
 <button 
  android:id="@+id/restart" 
  android:layout_width="wrap_content" 
  android:layout_height="wrap_content" 
  android:text="重置" 
  android:visibility="gone" /> 
 
</linearlayout> 

package com.example.chronometerdemo; 
 
import android.os.bundle; 
import android.os.systemclock; 
import android.app.activity; 
import android.view.menu; 
import android.view.view; 
import android.view.view.onclicklistener; 
import android.widget.button; 
import android.widget.chronometer; 
import android.widget.chronometer.onchronometerticklistener; 
 
public class mainactivity extends activity 
{ 
 chronometer time=null; 
 button restart=null; 
 
 @override 
 protected void oncreate(bundle savedinstancestate) { 
  super.oncreate(savedinstancestate); 
  setcontentview(r.layout.activity_main); 
   
  time=(chronometer) findviewbyid(r.id.chronometer); 
  restart=(button) findviewbyid(r.id.restart); 
   
  //设置起始时间和时间格式，然后开始计时 
  time.setbase(systemclock.elapsedrealtime()); 
  time.setformat("已用时间：%s"); 
  time.start(); 
   
  //给计时器添加监听器，当计时到达15s时，要重置 
  time.setonchronometerticklistener(new onchronometerticklistener() { 
    
   @override 
   public void onchronometertick(chronometer arg0) 
   { 
    if(systemclock.elapsedrealtime()-arg0.getbase()>=15000) 
    { 
     arg0.stop(); 
     restart.setvisibility(view.visible); 
    } 
     
   } 
  }); 
   
  //给按钮添加重置的效果 
  restart.setonclicklistener(new onclicklistener() { 
    
   @override 
   public void onclick(view arg0) 
   { 
    time.setbase(systemclock.elapsedrealtime()); 
    time.start(); 
    restart.setvisibility(view.gone); 
     
   } 
  }); 
 } 
 
 
 @override 
 public boolean oncreateoptionsmenu(menu menu) { 
  // inflate the menu; this adds items to the action bar if it is present. 
  getmenuinflater().inflate(r.menu.main, menu); 
  return true; 
 } 
  
}