[Android Pro] CountDownTimer倒计时

定时执行在一段时候后停止的倒计时,在倒计时执行过程中会在固定间隔时间得到通知(译者:触发onTick方法),下面的例子显示在一个文本框中显示一个30s倒计时:

new CountdownTimer(30000, 1000) {  
     public void onTick(long millisUntilFinished) {  
         mTextField.setText("seconds remaining: " + millisUntilFinished / 1000);  
     }  
     public void onFinish() {  
         mTextField.setText("done!");  
     }  
 }.start(); 

构造函数
         public CountDownTimer (long millisInFuture, long countDownInterval)
参数
        millisInFuture  从开始调用start()到倒计时完成并onFinish()方法被调用的毫秒数。(译者注:倒计时时间,单位毫秒)
        countDownInterval  接收onTick(long)回调的间隔时间。(译者注:单位毫秒)

公共方法
public final void cancel ()
         取消倒计时(译者:取消后,再次启动会重新开始倒计时)       
                 
public abstract void onFinish ()
         倒计时完成时被调用   

public abstract void onTick (long millisUntilFinished)
         固定间隔被调用
参数
         millisUntilFinished   倒计时剩余时间。

public synchronized final CountDownTimer start ()
         启动倒计时

    import android.app.Activity;  
    import android.os.Bundle;  
    import android.os.CountDownTimer;  
    import android.util.Log;  
    import android.view.View;  
    import android.view.View.OnClickListener;  
    import android.widget.Button;  
    import android.widget.TextView;  
       
    import com.test.R;  
       
    public class CountDownTimeActivity extends Activity implements OnClickListener {  
       
        TextView mTextView;  
        Button mButton1;  
        Button mButton2;  
         
        @Override  
        protected void onCreate(Bundle savedInstanceState) {  
           super.onCreate(savedInstanceState);  
            
           setContentView(R.layout.countdown);  
            
           mTextView = (TextView)findViewById(R.id.textView1);  
           mButton1 = (Button)findViewById(R.id.button1);  
           mButton2 = (Button)findViewById(R.id.button2);  
           mButton1.setOnClickListener(this);  
           mButton2.setOnClickListener(this);  
        }  
       
        CountDownTimer timer = new CountDownTimer(40000,1000) {  
            
           @Override  
           public void onTick(long millisUntilFinished) {  
               mTextView.setText("seconds remaining: " + millisUntilFinished / 1000);  
               try {  
                  Thread.sleep(1200);  
               } catch (InterruptedException e) {  
                  e.printStackTrace();  
               }  
               Log.e("CountDown",millisUntilFinished+"");  
           }  
            
           @Override  
           public void onFinish() {  
               mTextView.setText("done!");  
           }  
        };  
         
        @Override  
        public void onClick(View v) {  
           switch(v.getId()){  
           case R.id.button1:  
               timer.start();  
               break;  
           case R.id.button2:  
               timer.cancel();  
               break;  
           }  
            
        }  
    }  

 

posted @ 2016-02-19 21:46  demoblog  阅读(965)  评论(0编辑  收藏  举报