使用Android中的工作線程計算服務時間

Question

我想在發生特殊事件時開始計算我的服務時間。我想在工作線程中做到這一點。
甚至使用CountDownTimer()可以爲我做這個。
問題是，當我在IntentService類的OnHandleIntent()中使用此方法時，我收到一個錯誤：
java.lang.IllegalStateException: Handler (android.os.CountDownTimer$1) {235e78c} sending message to a Handler on a dead thread。

這是在時間到達目的地時計算時間和做特殊工作的最佳方式嗎？如果不是我可以如何？如果是，如何解決？謝謝。

我的服務代碼是：

import android.app.IntentService; 
import android.content.Context; 
import android.content.Intent; 
import android.os.CountDownTimer; 
import android.os.Environment; 
import android.util.Log; 

import java.io.BufferedReader; 
import java.io.File; 
import java.io.FileReader; 
import java.io.IOException; 
import java.io.OutputStreamWriter; 

public class TimeService extends IntentService { 



    public TimeService(){ 
     super(""); 

    } 

    @Override 
    protected void onHandleIntent(Intent intent) { 

     new CountDownTimer(20000,1000){ 

      @Override 
      public void onTick(long millisUntilFinished) { 
       System.out.println("Time remaining: "+millisUntilFinished/1000); 
      } 

      @Override 
      public void onFinish() { 
       System.out.println("done"); 
      } 
     }.start(); 

    } 



} 

Answer 1

I can not recommend to you to use IntentService. You should use regular service.

當意圖服務啓動時，它創建一個新的工作線程和完成那麼他們的任務時，它終止。但在你的情況下，你正在使用Countdowntimer，這是工作線程終止後運行，所以它拋出異常。

一個解決方案，你可以嘗試：

protected void onHandleIntent(Intent intent) { 
     Looper.prepare(); 
     new CountDownTimer(20000,1000){ 

      @Override 
      public void onTick(long millisUntilFinished) { 
       System.out.println("Time remaining: "+millisUntilFinished/1000); 
      } 

      @Override 
      public void onFinish() { 
       System.out.println("done"); 
       Looper.myLooper().quit(); 
      } 
     }.start(); 
     Looper.loop() ; 
    } 

Answer 2

Trying using your countdown timer in Service class as 

CountDownTimer countDownTimerVariable; 

In @Override 
public int onStartCommand(Intent intent, int flags, int startId) { 
    super.onStartCommand(intent, flags, startId); 

// based on your condition 
if(condition) 
    { 
    performCountDown(); 
    } 
} 

public void performCountDown() 
{ 
     countDownTimerVariable = new CountDownTimer(remainingMillisForCountDown, 1000) { 
         @Override 
         public void onFinish() { 
          //Action for when the timer has finished. 

          Log.i("timer finish", "finished"); 
      } 

    @Override 
         public void onTick(long millisUntilFinished) { 
          //Action for every tick of the countdown. 
          // timeCalculate((millisUntilFinished/1000)); 
          Log.i("timer finish", "finished" + (millisUntilFinished/1000) + " Countdown"); 

         } 
        }; 
        countDownTimerVariable.start(); 
} 


    and in destroy of service 

     @Override 
    public void onDestroy() { 
    // TODO Auto-generated method stub 
    this.unregisterReceiver(notifyServiceReceiver); 
    super.onDestroy(); 

    if(countDownTimerVariable != null) 
     countDownTimerVariable.cancel(); 
}