Question

在我的代码中，我使用json代码从在线MySQL数据库获取数据。问题是在某些情况下进度对话框永远不会完成，只是保持循环而不提取任何数据！并不总是如此，在大多数情况下，它就像一个魅力。

这是代码，任何想法!!!!

class LoadAllProducts extends AsyncTask<String, String, String> {
    ProgressDialog pDialog;

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(AllCategories.this);
        pDialog.setMessage("loading all categories");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    protected String doInBackground(String... args) 
    {

        String url_all_categories = "http://www.*****.com/****/****.php";

        List<NameValuePair> params = new ArrayList<NameValuePair>();

        JSONParser jParser = new JSONParser();
        JSONObject json = jParser.makeHttpRequest(url_all_categories,
                "GET", params);

        try {
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {

                categories = json.getJSONArray(TAG_CATEGORIES);

                for (int i = 0; i < categories.length(); i++) {
                    JSONObject c = categories.getJSONObject(i);
                    id = c.getString(TAG_CID);
                    name = c.getString(TAG_NAME);
                    descAR = c.getString(TAG_DESC_AR);
                    picture = c.getString(TAG_PICTURE);

                    HashMap<String, String> map = new HashMap<String, String>();

                    map.put(TAG_CID, id);
                    map.put(TAG_NAME, name);
                    map.put(TAG_DESC_AR, descAR);
                    map.put(TAG_PICTURE, picture);

                    categoriesList.add(map);
                }
            } else {
                Intent i = new Intent(getApplicationContext(),
                        NewCategory.class);
                i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(i);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return null;
    }

    protected void onPostExecute(String file_url) {

        pDialog.dismiss();
        adapter = new LazyAdapter(AllCategories.this, categoriesList);
        setListAdapter(adapter);
    }
}

Answer 1

替换pDialog.dismiss();

与

 pDialog.cancel();

Answer 2

int success;//Globally declared

在onPostExecute中执行：

 if (success == 1) {


} else {
                Intent i = new Intent(getApplicationContext(),
                        NewCategory.class);
                i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(i);
            }

和

HashMap<String, String> map = new HashMap<String, String>();

                    map.put(TAG_CID, id);
                    map.put(TAG_NAME, name);
                    map.put(TAG_DESC_AR, descAR);
                    map.put(TAG_PICTURE, picture);

                    categoriesList.add(map);

内部for循环创建问题

Answer 3

确保ProgressDialog的上下文是调用活动。那是： pDialog = new ProgressDialog（AllCategories.this）;

AllCategories应该是启动任务的活动。希望这有帮助

AsyncTask，doinBackground永远不会完成

3 个答案: