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Android計(jì)時(shí)與倒計(jì)時(shí)實(shí)現(xiàn)限時(shí)搶購(gòu)的5種方法

 更新時(shí)間:2018年02月08日 11:33:27   投稿:lijiao  
這篇文章主要為大家詳細(xì)介紹了Android計(jì)時(shí)與倒計(jì)時(shí)實(shí)現(xiàn)限時(shí)搶購(gòu)的5種方法,具有一定的參考價(jià)值,感興趣的小伙伴們可以參考一下

在購(gòu)物網(wǎng)站的促銷活動(dòng)中一般都有倒計(jì)時(shí)限制購(gòu)物時(shí)間或者折扣的時(shí)間,這些都是如何實(shí)現(xiàn)的呢?

在一個(gè)安卓客戶端項(xiàng)目中恰好遇到了類似的問題,一開始使用的是Timer與 TimerTask, 雖然此方法通用,但后來考慮在安卓中是否有更佳的方案,于是乎共找到以下五種實(shí)現(xiàn)方案,另外還有一種使用CountDownTimer進(jìn)行計(jì)時(shí)的方面,我會(huì)在單獨(dú)的文章中進(jìn)行介紹

效果如圖:

方法一

Timer與TimerTask(Java實(shí)現(xiàn))

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(jìn)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(不占用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(jiǎn)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);  
    runnable.run();  
  }    
  
  Handler handler = new Handler();  
  Runnable runnable = new Runnable() {  
    @Override  
    public void run() {  
      recLen++;  
      txtView.setText("" + recLen);  
      handler.postDelayed(this, 1000);  
    }  
  };  
}  

計(jì)時(shí)與倒計(jì)時(shí)

方法1,方法2和方法3,都是倒計(jì)時(shí)
方法4,方法5,都是計(jì)時(shí)
計(jì)時(shí)和倒計(jì)時(shí),都可使用上述方法實(shí)現(xiàn)(代碼稍加改動(dòng))

UI線程比較

方法1,方法2和方法3,都是在UI線程實(shí)現(xiàn)的計(jì)時(shí);
方法4和方法5,是另開Runnable線程實(shí)現(xiàn)計(jì)時(shí)

實(shí)現(xiàn)方式比較

方法1,采用的是Java實(shí)現(xiàn),即Timer和TimerTask方式;
其它四種方法,都采用了Handler消息處理

推薦使用

如果對(duì)UI線程交互要求不很高,可以選擇方法2和方法3
如果考慮到UI線程阻塞,嚴(yán)重影響到用戶體驗(yàn),推薦使用方法4,另起線程單獨(dú)用于計(jì)時(shí)和其它的邏輯處理
方法5,綜合了前幾種方法的優(yōu)點(diǎn),是最簡(jiǎn)的

以上就是本文的全部?jī)?nèi)容,希望對(duì)大家的學(xué)習(xí)有所幫助,也希望大家多多支持腳本之家。

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