实现Android计时与倒计时方法

来源：互联网发布：修改pdf文件的软件编辑：程序博客网时间：2024/05/20 19:32

转自http://blog.csdn.net/wangqilin8888/article/details/7415601

今天给大家介绍几个Android中实现计时和倒计时的几种方法，这几种方法也许今后会帮上大家，现贴出来如下：

方法一

Timer与TimerTask（Java实现）

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public class timerTask extendsActivity{
  
    privateintrecLen = 11;
    privateTextView txtView;
    Timer timer =newTimer();
  
    publicvoidonCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
          
        setContentView(R.layout.timertask);
        txtView = (TextView)findViewById(R.id.txttime);
          
        timer.schedule(task,1000,1000);      // timeTask
    }   
  
    TimerTask task =newTimerTask() {
        @Override
        publicvoidrun() {
  
            runOnUiThread(newRunnable() {     // UI thread
                @Override
                publicvoidrun() {
                    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）

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public class timerTask extendsActivity{
    privateintrecLen = 11;
    privateTextView txtView;
    Timer timer =newTimer();
  
    publicvoidonCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
  
        setContentView(R.layout.timertask);
        txtView = (TextView)findViewById(R.id.txttime);
  
        timer.schedule(task,1000,1000);      // timeTask
    }   
  
    finalHandler handler =newHandler(){
        @Override
        publicvoidhandleMessage(Message msg){
            switch(msg.what) {
            case1:
                txtView.setText(""+recLen);
                if(recLen <0){
                    timer.cancel();
                    txtView.setVisibility(View.GONE);
                }
            }
        }
    };
  
    TimerTask task =newTimerTask() {
        @Override
        publicvoidrun() {
            recLen--;
            Message message =newMessage();
            message.what =1;
            handler.sendMessage(message);
        }
    };
}

方法三

Handler与Message（不用TimerTask）

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public class timerTask extendsActivity{
    privateintrecLen = 11;
    privateTextView txtView;
  
    publicvoidonCreate(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);
    }  
  
    finalHandler handler =newHandler(){
  
        publicvoidhandleMessage(Message msg){        // handle message
            switch(msg.what) {
            case1:
                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）

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public class timerTask extendsActivity{
    privateintrecLen = 0;
    privateTextView txtView;
  
    publicvoidonCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
  
        setContentView(R.layout.timertask);
        txtView = (TextView)findViewById(R.id.txttime);
          
        newThread(newMyThread()).start();         // start thread
    }   
  
    finalHandler handler =newHandler(){         // handle
        publicvoidhandleMessage(Message msg){
            switch(msg.what) {
            case1:
                recLen++;
                txtView.setText(""+ recLen);
            }
            super.handleMessage(msg);
        }
    };
  
    publicclassMyThread implementsRunnable{     // thread
        @Override
        publicvoidrun(){
            while(true){
                try{
                    Thread.sleep(1000);    // sleep 1000ms
                    Message message =newMessage();
                    message.what =1;
                    handler.sendMessage(message);
                }catch(Exception e) {
                }
            }
        }
    }
}

方法五

Handler与Runnable（最简单型）

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public class timerTask extendsActivity{
    privateintrecLen = 0;
    privateTextView txtView;
  
    publicvoidonCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
  
        setContentView(R.layout.timertask);
        txtView = (TextView)findViewById(R.id.txttime);
          
        handler.postDelayed(runnable,1000);
    }   
  
    Handler handler =newHandler();
    Runnable runnable =newRunnable() {
        @Override
        publicvoidrun() {
            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