你可以调用AsyncTask的get()方法(或者重载的get(long, TimeUnit))。此方法将阻塞，直到AsyncTask完成它的工作，此时它将返回Result。

在创建/启动异步任务和调用get方法之间做其他工作是明智的，否则你不能非常有效地利用异步任务。

您可以编写自己的侦听器。它和HelmiB的答案一样，但看起来更自然:

创建监听器接口:

public interface myAsyncTaskCompletedListener {
    void onMyAsynTaskCompleted(int responseCode, String result);
}

然后写你的异步任务:

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

    private myAsyncTaskCompletedListener listener;
    private int responseCode = 0;

    public myAsyncTask() {
    }

    public myAsyncTask(myAsyncTaskCompletedListener listener, int responseCode) {
        this.listener = listener;
        this.responseCode = responseCode;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }


    @Override
    protected String doInBackground(String... params) {
        String result;
        String param = (params.length == 0) ? null : params[0];
        if (param != null) {
            // Do some background jobs, like httprequest...
            return result;
        }
        return null;
    }

    @Override
    protected void onPostExecute(String finalResult) {
        super.onPostExecute(finalResult);
        if (!isCancelled()) {
            if (listener != null) {
                listener.onMyAsynTaskCompleted(responseCode, finalResult);
            }
        }
    }
}

最后在activity中实现监听器:

public class MainActivity extends AppCompatActivity implements myAsyncTaskCompletedListener {

    @Override
    public void onMyAsynTaskCompleted(int responseCode, String result) {

        switch (responseCode) {
            case TASK_CODE_ONE: 
                // Do something for CODE_ONE
                break;
            case TASK_CODE_TWO:
                // Do something for CODE_TWO
                break;
            default: 
                // Show some error code
        }        
    }

这是你如何调用asyncTask:

 protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Some other codes...
        new myAsyncTask(this,TASK_CODE_ONE).execute("Data for background job");
        // And some another codes...
}

你可以调用AsyncTask的get()方法(或者重载的get(long, TimeUnit))。此方法将阻塞，直到AsyncTask完成它的工作，此时它将返回Result。

在创建/启动异步任务和调用get方法之间做其他工作是明智的，否则你不能非常有效地利用异步任务。

为什么人们把事情搞得这么难。

这应该足够了。

不要在异步任务上实现onPostExecute，而是在Activity上实现它:

public class MainActivity extends Activity 
{

@Override
public void onCreate(Bundle savedInstanceState) {

    //execute the async task 
    MyAsyncTask task = new MyAsyncTask(){
            protected void onPostExecute(String result) {
                //Do your thing
            }       

    }

    task.execute("Param");

}


}

我觉得下面的方法很简单。

我已经声明了一个回调接口

public interface AsyncResponse {
    void processFinish(Object output);
}

然后创建异步任务来响应所有类型的并行请求

 public class MyAsyncTask extends AsyncTask<Object, Object, Object> {

    public AsyncResponse delegate = null;//Call back interface

    public MyAsyncTask(AsyncResponse asyncResponse) {
        delegate = asyncResponse;//Assigning call back interfacethrough constructor
    }

    @Override
    protected Object doInBackground(Object... params) {

      //My Background tasks are written here

      return {resutl Object}

    }

    @Override
    protected void onPostExecute(Object result) {
        delegate.processFinish(result);
    }

}

然后在活动类中单击按钮时调用异步任务。

public class MainActivity extends Activity{

    @Override
    public void onCreate(Bundle savedInstanceState) {

    Button mbtnPress = (Button) findViewById(R.id.btnPress);

    mbtnPress.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                MyAsyncTask asyncTask =new MyAsyncTask(new AsyncResponse() {

                    @Override
                    public void processFinish(Object output) {
                        Log.d("Response From Asynchronous task:", (String) output);

                        mbtnPress.setText((String) output);
                   }
                });

                asyncTask.execute(new Object[] { "Your request to aynchronous task class is giving here.." });


            }
        });

    }



}

谢谢

有以下几种选择:

Nest the AsyncTask class within your Activity class. Assuming you don't use the same task in multiple activities, this is the easiest way. All your code stays the same, you just move the existing task class to be a nested class inside your activity's class. public class MyActivity extends Activity { // existing Activity code ... private class MyAsyncTask extends AsyncTask<String, Void, String> { // existing AsyncTask code ... } } Create a custom constructor for your AsyncTask that takes a reference to your Activity. You would instantiate the task with something like new MyAsyncTask(this).execute(param1, param2). public class MyAsyncTask extends AsyncTask<String, Void, String> { private Activity activity; public MyAsyncTask(Activity activity) { this.activity = activity; } // existing AsyncTask code ... }