【Android】Android实现计时与倒计时的几种方法 Timer与TimerTask

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);

  }

 };

}