AsyncTask的片段中没有更新的用户界面 [英] AsyncTask in fragments not updating UI

问题描述

我使用 FragmentPagerAdapter 刷卡片段和使用的AsyncTask 更新GridView的，但它没有更新的用户界面。

它不更新用户界面，也没有抛我试图检查流量及其运行GalleryTab片段两次的错误......而无法理解的问题。

我的code： -

 公共类GalleryTab扩展片段{
            GridView控件GridView控件;
            ProgressDialog mProgressDialog;
            GridViewAdapter适配器;
            公开名单＆LT; GalleryList＆GT; phonearraylist = NULL;
            查看图。
            私人的WeakReference＆LT; RemoteDataTask＆GT; asyncTaskWeakRef;

        公共静态片段的newInstance（上下文的背景下）{
            GalleryTab F =新GalleryTab（）;
        返回F;
        }

        @覆盖
        公共查看onCreateView（LayoutInflater充气，容器的ViewGroup，
                捆绑savedInstanceState）{
            //充气的布局该片段
            鉴于= inflater.inflate（R.layout.activity_gallery_tab，NULL）;
             setRetainInstance（真正的）;
                startNewAsyncTask（）;
            //新RemoteDataTask（本）.execute（）;
            返回inflater.inflate（R.layout.activity_gallery_tab，集装箱，假）;
        }

        // RemoteDataTask的AsyncTask
            私有类RemoteDataTask扩展的AsyncTask＆LT;虚空，虚空，虚空＆GT; {
                私人的WeakReference＆LT; GalleryTab＆GT; fragmentWeakRef;

                私人RemoteDataTask（GalleryTab gallerytab）{
                    this.fragmentWeakRef =新的WeakReference＆LT; GalleryTab＆GT;（gallerytab）;
                }

                @覆盖
                在preExecute保护无效（）{
                    super.on preExecute（）;

                }

                @覆盖
                保护无效doInBackground（虚空...... PARAMS）{
                    //创建数组

                    phonearraylist =新的ArrayList＆LT; GalleryList＆GT;（）;
                    尝试 {
                        的for（int i = 0; I＆LT; = 6;我++）{
                            GalleryList地图=新GalleryList（）;
                            map.setGallery（http://oi39.tinypic.com/21oydxs.jpg）;
                            的System.out.println（打印!!!!  - + I）;
                            phonearraylist.add（图）
                        }
                    }赶上（ParseException的E）{
                        Log.e（错误，e.getMessage（））;
                        e.printStackTrace（）;
                    }

                    返回null;
                }

                @覆盖
                保护无效onPostExecute（无效的结果）{
                    //如果（this.fragmentWeakRef.get（）！= NULL）{
                    适配器=新GridViewAdapter（getActivity（），phonearraylist）;
                    的System.out.println（打印尺寸 - + phonearraylist.size（））;
                    gridview的=（GridView控件）view.findViewById（R.id.gridview）;
                    gridview.setAdapter（适配器）;

                // mProgressDialog.dismiss（）;
                    //}
                }
            }
            私人无效startNewAsyncTask（）{
                RemoteDataTask的AsyncTask =新RemoteDataTask（本）;
                this.asyncTaskWeakRef =新的WeakReference＆LT; RemoteDataTask＆GT;（AsyncTask的）;
                asyncTask.execute（）;
            }
    }
 

解决方案

您必须找出你的GridView onCreateView的ID（）方法，因为它返回的视图...

 的GridView =（GridView控件）view.findViewById（R.id.gridview）;
 

是的，如果你有做在intialize查看的对象，然后只需更换：

 返回inflater.inflate（R.layout.activity_gallery_tab，集装箱，假）;
 

到

 返回查看;
 

I am using FragmentPagerAdapter to swipe Fragment and using AsyncTask to update gridview but its not updating the UI.

Its not updating the UI and also not throwing any error I tried to check the flow and its running GalleryTab fragment twice...and unable to understand the problem .

My code:-

public class GalleryTab extends Fragment {
            GridView gridview;
            ProgressDialog mProgressDialog;
            GridViewAdapter adapter;
            public List<GalleryList> phonearraylist = null;
            View view;
            private WeakReference<RemoteDataTask> asyncTaskWeakRef;

        public static Fragment newInstance(Context context) {
            GalleryTab f = new GalleryTab();
        return f;
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            // Inflate the layout for this fragment
            view = inflater.inflate(R.layout.activity_gallery_tab, null);
             setRetainInstance(true);
                startNewAsyncTask();
            //new RemoteDataTask(this).execute();
            return inflater.inflate(R.layout.activity_gallery_tab, container, false);
        }

        // RemoteDataTask AsyncTask
            private class RemoteDataTask extends AsyncTask<Void, Void, Void> {
                private WeakReference<GalleryTab> fragmentWeakRef;

                private RemoteDataTask (GalleryTab gallerytab) {
                    this.fragmentWeakRef = new WeakReference<GalleryTab>(gallerytab);
                }

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

                } 

                @Override
                protected Void doInBackground(Void... params) {
                    // Create the array

                    phonearraylist = new ArrayList<GalleryList>();
                    try {
                        for (int i = 0; i <= 6; i++) {
                            GalleryList map = new GalleryList();
                            map.setGallery("http://oi39.tinypic.com/21oydxs.jpg");
                            System.out.println("PRINT!!!!--  "+ i);
                            phonearraylist.add(map);
                        }
                    } catch (ParseException e) {
                        Log.e("Error", e.getMessage());
                        e.printStackTrace();
                    }

                    return null;
                }

                @Override
                protected void onPostExecute(Void result) {
                    // if (this.fragmentWeakRef.get() != null) {
                    adapter = new GridViewAdapter(getActivity(), phonearraylist);
                    System.out.println("PRINT SIZE --  "+ phonearraylist.size());
                    gridview = (GridView)view.findViewById(R.id.gridview);
                    gridview.setAdapter(adapter);

                //  mProgressDialog.dismiss();
                    // }
                }
            }
            private void startNewAsyncTask() {
                RemoteDataTask asyncTask = new RemoteDataTask(this);
                this.asyncTaskWeakRef = new WeakReference<RemoteDataTask >(asyncTask );
                asyncTask.execute();
            }
    }

解决方案

You have to find out your id of GridView onCreateView() method because it returns the view...

gridview = (GridView)view.findViewById(R.id.gridview);

And yes if you have Make a object of View at intialize then just replace :

return inflater.inflate(R.layout.activity_gallery_tab, container, false);

to

return view;

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