Android實現計時與倒計時的常用方法小結_Android

本文執行個體總結了Android實現計時與倒計時的常用方法。分享給大家供大家參考，具體如下：

方法一

Timer與TimerTask（Java實現）

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與Handler（不用Timer的改進型）

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與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與Thread（不佔用UI線程）

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與Runnable（最簡單型）

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);     }   }; }

計時與倒計時

方法1，方法2和方法3，都是倒計時
方法4，方法5，都是計時
計時和倒計時，都可使用上述方法實現（代碼稍加改動）

UI線程比較

方法1，方法2和方法3，都是在UI線程實現的計時；
方法4和方法5，是另開Runnable線程實現計時

實現方式比較

方法1，採用的是Java實現，即Timer和TimerTask方式；
其它四種方法，都採用了Handler訊息處理

推薦使用

如果對UI線程互動要求不很高，可以選擇方法2和方法3
如果考慮到UI線程阻塞，嚴重影響到使用者體驗，推薦使用方法4，另起線程單獨用於計時和其它的邏輯處理
方法5，綜合了前幾種方法的優點，是最簡的

希望本文所述對大家Android程式設計有所協助。