我一直在使用AsyncTask下載某個文件，并經歷了一些教程，只是未能使進度條隨著下載而移動。代碼是和 AsyncTask 調用一個方法來執行 HTTP 連接，然后返回以正確的方式對數據進行排序，以便為應用程序操作它這是我的AsynTask，在主要活動    private class getFood extends AsyncTask<Void, Integer, Cursor> {    private ProgressDialog mProgressDialog;    @Override    protected Cursor doInBackground(Void... params) {        // Create URL object        String site = "https://afternoon-ridge-50060.herokuapp.com/allsnacks";        URL url = createUrl(site);        // Perform HTTP request to the URL and receive a JSON response back        String jsonResponse = null;        try {            String jsonResponseEmpty = "";            // If the URL is null, then return early.            if (url == null) {                jsonResponse = jsonResponseEmpty;            }            HttpURLConnection urlConnection = null;            InputStream inputStream = null;            try {                assert url != null;                urlConnection = (HttpURLConnection) url.openConnection();                urlConnection.setReadTimeout(20000 /* milliseconds */);                urlConnection.setConnectTimeout(25000 /* milliseconds */);                urlConnection.setRequestMethod("GET");                urlConnection.setRequestProperty("Authorization", "\"token\": " + token);                urlConnection.connect();