Android实现计时与倒计时的方法汇总

时间：2021-01-14 11:15:14|栏目：Android代码|点击：次

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