protected void onPostExecute错误

Question

当我尝试实现onPostExecute方法时，它给我一个错误，删除@Override并且需要调用超类或方法。但是，我确实称之为超类等。这是我的Asynctask代码。

    public class parsenfill extends AsyncTask<Void,Void,Void> {

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

        try {
        JsonParsing parse = new JsonParsing(url);
        parse.parseFile(3, urls);
        return null;
        }
        catch(Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void...voids ) {
        super.onPostExecute(voids);
                    //Body of method

    }
}

Answer 1

从方法签名中删除...。 onPostExecute的参数类型是doInBackground()的返回类型，即您的案例中仅为Void。

Answer 2

试试这个

private class MyAsyncClass extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {

        /**
         * invoked on the UI thread before the task is executed. This step
         * is normally used to setup the task, for instance by showing a
         * progress bar in the user interface.
         */

        super.onPreExecute();
    }

    @Override
    protected Void doInBackground(Void... params) {
        /**
         * Invoked on the background thread immediately after onPreExecute()
         * finishes executing. This step is used to perform background
         * computation that can take a long time. The parameters of the
         * asynchronous task are passed to this step.
         */
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        /**
         * Invoked on the UI thread after the background computation
         * finishes. The result of the background computation is passed to
         * this step as a parameter.
         */
        super.onPostExecute(result);
    }

}

然后你必须在这样的UI线程上调用这个 async class 。

new MyAsyncClass().execute();

Answer 3

错：

 @Override
protected void onPostExecute(Void...voids ) {
    super.onPostExecute(voids);
                //Body of method

}

因为...代表字符串数组，你的背景返回无效。

正确：

@Override
protected void onPostExecute(Void voids ) {
    super.onPostExecute(voids);
                //Body of method

}