Android实现计时与倒计时的常用方法小结

本文实例总结了android实现计时与倒计时的常用方法。分享给大家供大家参考，具体如下：

方法一

timer与timertask（java实现）

public class timertask extends activity{ 
  private int reclen = 11; 
  private textview txtview; 
  timer timer = new timer(); 
  public void oncreate(bundle savedinstancestate){ 
    super.oncreate(savedinstancestate); 
    setcontentview(r.layout.timertask); 
    txtview = (textview)findviewbyid(r.id.txttime); 
    timer.schedule(task, 1000, 1000);    // timetask 
  }   
  timertask task = new timertask() { 
    @override 
    public void run() { 
      runonuithread(new runnable() {   // ui thread 
        @override 
        public void run() { 
          reclen--; 
          txtview.settext(""+reclen); 
          if(reclen < 0){ 
            timer.cancel(); 
            txtview.setvisibility(view.gone); 
          } 
        } 
      }); 
    } 
  }; 
}

方法二

timertask与handler（不用timer的改进型）

public class timertask extends activity{ 
  private int reclen = 11; 
  private textview txtview; 
  timer timer = new timer(); 
  public void oncreate(bundle savedinstancestate){ 
    super.oncreate(savedinstancestate); 
    setcontentview(r.layout.timertask); 
    txtview = (textview)findviewbyid(r.id.txttime); 
    timer.schedule(task, 1000, 1000);    // timetask 
  }   
  final handler handler = new handler(){ 
    @override 
    public void handlemessage(message msg){ 
      switch (msg.what) { 
      case 1: 
        txtview.settext(""+reclen); 
        if(reclen < 0){ 
          timer.cancel(); 
          txtview.setvisibility(view.gone); 
        } 
      } 
    } 
  }; 
  timertask task = new timertask() { 
    @override 
    public void run() { 
      reclen--; 
      message message = new message(); 
      message.what = 1; 
      handler.sendmessage(message); 
    } 
  }; 
}

方法三

handler与message（不用timertask）

public class timertask extends activity{ 
  private int reclen = 11; 
  private textview txtview; 
  public void oncreate(bundle savedinstancestate) {  
    super.oncreate(savedinstancestate);  
    setcontentview(r.layout.timertask);  
    txtview = (textview)findviewbyid(r.id.txttime); 
    message message = handler.obtainmessage(1);   // message 
    handler.sendmessagedelayed(message, 1000); 
  }  
  final handler handler = new handler(){ 
    public void handlemessage(message msg){     // handle message 
      switch (msg.what) { 
      case 1: 
        reclen--; 
        txtview.settext("" + reclen); 
        if(reclen > 0){ 
          message message = handler.obtainmessage(1); 
          handler.sendmessagedelayed(message, 1000);   // send message 
        }else{ 
          txtview.setvisibility(view.gone); 
        } 
      } 
      super.handlemessage(msg); 
    } 
  }; 
}

方法四

handler与thread（不占用ui线程）

public class timertask extends activity{ 
  private int reclen = 0; 
  private textview txtview; 
  public void oncreate(bundle savedinstancestate){ 
    super.oncreate(savedinstancestate); 
    setcontentview(r.layout.timertask); 
    txtview = (textview)findviewbyid(r.id.txttime); 
    new thread(new mythread()).start();     // start thread 
  }   
  final handler handler = new handler(){     // handle 
    public void handlemessage(message msg){ 
      switch (msg.what) { 
      case 1: 
        reclen++; 
        txtview.settext("" + reclen); 
      } 
      super.handlemessage(msg); 
    } 
  }; 
  public class mythread implements runnable{   // thread 
    @override 
    public void run(){ 
      while(true){ 
        try{ 
          thread.sleep(1000);   // sleep 1000ms 
          message message = new message(); 
          message.what = 1; 
          handler.sendmessage(message); 
        }catch (exception e) { 
        } 
      } 
    } 
  } 
}

方法五

handler与runnable（最简单型）

public class timertask extends activity{ 
  private int reclen = 0; 
  private textview txtview; 
  public void oncreate(bundle savedinstancestate){ 
    super.oncreate(savedinstancestate); 
    setcontentview(r.layout.timertask); 
    txtview = (textview)findviewbyid(r.id.txttime); 
    handler.postdelayed(runnable, 1000); 
  }   
  handler handler = new handler(); 
  runnable runnable = new runnable() { 
    @override 
    public void run() { 
      reclen++; 
      txtview.settext("" + reclen); 
      handler.postdelayed(this, 1000); 
    } 
  }; 
}

计时与倒计时

方法1，方法2和方法3，都是倒计时
方法4，方法5，都是计时
计时和倒计时，都可使用上述方法实现（代码稍加改动）

ui线程比较

方法1，方法2和方法3，都是在ui线程实现的计时；
方法4和方法5，是另开runnable线程实现计时

实现方式比较

方法1，采用的是java实现，即timer和timertask方式；
其它四种方法，都采用了handler消息处理

推荐使用

如果对ui线程交互要求不很高，可以选择方法2和方法3
如果考虑到ui线程阻塞，严重影响到用户体验，推荐使用方法4，另起线程单独用于计时和其它的逻辑处理
方法5，综合了前几种方法的优点，是最简的

希望本文所述对大家android程序设计有所帮助。