定期执行的AsyncTask类对象：更新时间 [英] Periodically Executing AsyncTask Class object: Updated

问题描述

什么是重新开始的AsyncTask它已经完成之后的最佳方式。 我的应用程序，我需要做一些更新UI每30秒左右的后台处理。

what is the best way to start AsyncTask again after it has completed. My application is where I need to do some background processing that updates UI every 30 secs or so.

所以将这个好

MyAsyncTask t;

onCreate(){
 postDelayed(myrunnable,..)
}

myrunnable(){
if(t && t.getStatus()== FINISHED){
t = new MyAsyncTask();
t.execute()

 postDelayed(myrunnable,30000)
}else
postDelayed(myrunnable,2000)
}

更新：编辑在code，所以如果这个序列似乎有效，请说是或建议更改

Update:Edited the code, So if this sequence seems valid please say yes or suggest changes

推荐答案

您可以：

• 注册类负责AsyncTask的执行作为听众你的AsyncTask的。
• 当任务完成后，在doInBackground方法在年底前实施在AsyncTask的回调。
• 当您收到回调执行下一个AsyncTask的。

例： 您的侦听器接口：

Example: Your listener interface:

public interface IProgress {

  public void onProgressUpdate(final boolean isFinished);

}

您的活动实现IProgress：

Your activity implements IProgress:

public class MyActivity implements IProgress {


  public void onProgressUpdate(final boolean isFinished) {

    if (isFinished) {
        // delayed execution
        myHandler.postDelayed(new MyRunnable(MyActivity.this), 30000);
    }
  }

您的AsyncTask包含IProgress实例，并调用onProgressUpdate在doInBackground年底或onPostExecute：

Your AsyncTask contains a IProgress instance and you call onProgressUpdate at the end of doInBackground or in onPostExecute:

...

  private final IProgress progressListener;

  public MyAsyncTask( final IProgress progressListener) {
    super();    
    this.progressListener = progressListener;    
  }

...

  @Override
  protected void onPostExecute(final int result) {
    progressListener.onProgressUpdate(true);
    super.onPostExecute(result);
  }

对于postDelayed创建runnnable：

Create a runnnable for the postDelayed:

  protected class MyRunnable implements Runnable {

    private final IProgress progressListener;

    public MyRunnable(final IProgress progressListener) {
      super();
      this.progressListener= progressListener;
    }

    public void run() {
            new MyAsyncTask(progressListener).execute();
    }
  };

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