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Android实现计时与倒计时(限时抢购)的几种方法(线程)

 
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方法一
Timer与TimerTask(Java实现)

[java] view plaincopy
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);   
        runnable.run();  
    }      
  
    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

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