AsyncTask <String,Void,Void>如何工作？

Question

谁能告诉我这里出了什么问题？

public class BackgroungTask extends AsyncTask<String, Void, Void> {

    public Void doInBackground(String... params) {
       //tasks
       return;  //error occurs here!
    }

    public void onPostExecute(Void result) {
        //codes
    }
}

上述类不依赖于返回值.所以onPostExceute()只是执行那里写的代码.

提前致谢!

Answer 1

只返回null.

public class BackgroungTask extends AsyncTask<String, Void, Void> {

    public Void doInBackground(String... params) {
       //tasks
       return null; 
    }

    public void onPostExecute(Void result) {
        //codes
    }
}

Answer 2

我想你必须使用"return null;" 而不只是"返回;",就像Void一个围绕通常的"空白"值的类.

Answer 3

在doInBackGround返回零,因为Void是一个对象(不=空隙)..

public class BackgroungTask extends AsyncTask<String, Void, Void> {

public Void doInBackground(String... params) {
   //tasks
   return null;  //error occurs here!
}

public void onPostExecute(Void result) {
    //codes
}
}