带有ProgressDialog的外部AsyncTask类[更新:并返回？]

public class MyAsyncTask extends AsyncTask<Void, Integer, String> {

    private Context mContext;
    private OnTaskCompletedListener mListener;
    private ProgressDialog mProgressDialog;

    public MyAsyncTask(Context context, OnTaskCompletedListener listener) {
        mContext = context;
        mListener = listener;
        mProgressDialog = new ProgressDialog(mContext);
        mProgressDialog.setMessage("Loading...");
    }

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

    @Override
    protected String doInBackground(Void... params) {
        // Do your background work here
        return "Your result";
    }

    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);
        mProgressDialog.dismiss();
        mListener.onTaskCompleted(result);
    }

    public interface OnTaskCompletedListener {
        void onTaskCompleted(String result);
    }
}

MyAsyncTask task = new MyAsyncTask(this, new MyAsyncTask.OnTaskCompletedListener() {
    @Override
    public void onTaskCompleted(String result) {
        // Update your UI here
    }
});
task.execute();