机器人的AsyncTask与线程

问题描述

我创建了一个AsyncTask的，并在其doInBackground（）方法，我开始这样一个主题：

I created an asynctask and in its doInBackground() method i started a thread like this:

private class myAsyntask extends Asynctask{

    doInBackground(){
    Thread t = new Thread(new Runnable(){
     public void run()
     {
        while(someBoolean!=true){
        Thread.currentThread.sleep(100);
        }
     }
     });
    }
   onPostExecute(){
  //do something related to that variable
  }
}

问题，我面对的是的第1次迭代后的视频下载（）， onPostExecute（）被调用，相反，我认为的AsyncTask将运行在后台的主题，并当布尔值为true onPostexecute（）是called.I我无法理解为什么会这样？

problem I am facing is after 1st iteration of Thread.sleep() , onPostExecute() is called , instead I thought that asynctask will run this thread on background and when that boolean is true onPostexecute() is called.I am not able to understand why this happens ?

推荐答案

AsyncTask的自动为您创建一个新的主题，让您在做的一切doInBackground（）是另一线程。
你在做什么是这样的：

AsyncTask automatically creates a new Thread for you, so everything you do in doInBackground() is on another thread.
What you are doing is this:

1. AsyncTask的创建一个新的线程和运行 doInBackground（）。
2. 在一个新的线程（ T ）从AsyncTask的线程创建的。
3. doInBackground（）完成，因为它的作用是创建线程t，从而跳到 onPostExecute（）。
4. 在线程t仍然会在后台（但是，你不叫启动（）在 T 运行的，这意味着它不启动）。

1. AsyncTask creates a new Thread and runs doInBackground().
2. a new Thread (t) is created from the AsyncTask-Thread.
3. doInBackground() is completed, as all it does is create the Thread t and thus jumps to onPostExecute().
4. Thread t would still be running in the background (however, you do not call start() on t, meaning that it is not started).

相反，你希望你的 doInBackground（）方法看起来是这样的：

Instead you want your doInBackground() method to look something like this:

doInBackground(){
    while(someBoolean!=true){
        //Perform some repeating action.
        Thread.sleep(100);
    }
}

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