Android实现计时与倒计时(限时抢购)的几种方法

/*
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）
*/
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);  
    }  
};  

}