关于使用凌空库加载项微调 [英] Regarding loading items to the spinner using volley library

问题描述

我试图加载的项目里面的微调我的 MainActivity toolbar.Inside MainActivity 有一个叫做片段 HomeFragment 。这片段包含 SlidingTabLayout 有一次我点击不同的标签，我需要不同的数据集加载到上面提到的微调。

I am trying to load items to the spinner inside my MainActivity toolbar.Inside MainActivity there is a fragment called HomeFragment. And that fragment contains SlidingTabLayout and once I click different tabs I need to load different data sets to the above mentioned spinner.

下面是它的样子：

我已经实现在 MainActivity 方法将数据添加到微调：

I have implemented method inside MainActivity to add data to the spinner :

    public void addItemsToSpinner(final Collection<String> collection) {

        ArrayList<String> list = new ArrayList<>();
        list.addAll(collection);

        CustomSpinnerAdapter spinAdapter = new CustomSpinnerAdapter(getApplicationContext(), list);
        subCategories_spinner.setAdapter(spinAdapter);
        subCategories_spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> adapter, View v, int position, long id) {
                // On selecting a spinner item
                String item = adapter.getItemAtPosition(position).toString();

                // Showing selected spinner item
//                Toast.makeText(getApplicationContext(), "Selected  : " + item,
//                        Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> arg0) {
                // TODO Auto-generated method stub

            }
        });

    }

和里面我 HomeActivity 我已经设置 OnPageChangeLister 到 SlidingTabLayout 象下面这样：

And inside my HomeActivity I have set OnPageChangeLister to SlidingTabLayout like below :

mTabs.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
                if (firstScrolled) {
                    // Here log-cat gives me I/Position: On page scrolled - 0 which means on stating app this line executed. But data not set to the spinner.
                   // Log.i("Position", "On page scrolled - " + position);
                    volleySubCatFilter("women");
                    ((MainActivity) getActivity()).addItemsToSpinner(subs);//debug console subs (ArrayList) size given as 0 here
                    firstScrolled = false;
                }


            }

            @Override
            public void onPageSelected(int position) {
                if (position == 0) {
                   // Log.i("Position", "On page selected - " + position);
                    volleySubCatFilter("women");
                   ((MainActivity) getActivity()).addItemsToSpinner(subs);

                }
                if (position == 1) {
                   // Log.i("Position", "On page selected - " + position);
                    volleySubCatFilter("men");
                    ((MainActivity) getActivity()).addItemsToSpinner(subs);

                }
                if (position == 2) {
                   // Log.i("Position", "On page selected - " + position);
                    volleySubCatFilter("household%20goods");
                   ((MainActivity) getActivity()).addItemsToSpinner(subs);

                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

通过使用 volleySubCatFilter（category_here）的; 方法我检索凌空向服务器请求数据，并工作正常。

With use of volleySubCatFilter("category_here"); method I retrieve data from volley request to the server and it is working fine.

我的问题是第一次加载应用程序的女性标签被选中，但没有数据加载到spinner.But我试图Log.i（位置 在页面滚动 - +位置）; 并尽快应用程序加载它给了我 I /职务：在页面滚动 - 0 在我的日志，cat.But数据犯规负荷。
Debuging行（（MainActivity）getActivity（））。addItemsToSpinner（潜艇） 0告诉我items.Once preSS另一个选项卡，然后它开始加载属于$ P数据$ pvious标签。例如： - pressing MEN 标签加载的应用程序中获取数据后权属于女性 tab.Then我点击它开始加载数据的任何选项卡上属于 WOMEN 标签。

The problem I have is first time loading the application WOMEN tab is selected and but no data loaded to the spinner.But I tried with Log.i("Position", "On page scrolled - " + position); and as soon as the app loaded it gives me I/Position: On page scrolled - 0 in my log-cat.But data doesnt load. Debuging line ((MainActivity) getActivity()).addItemsToSpinner(subs) tells 0 items.Once I press another tab then it starts loading data which belongs to previous tab. Example :- Pressing MEN tab right after app loaded getting data belongs to WOMEN tab.Then I click on any tab it start loading data belongs to WOMEN tab.

如果我介绍这个问题的数据加载到微调是一步
  后面。

If I brief this problem data loading to the spinner is one step behind.

如果有人给我建议的方式来摆脱这种bug.Thanks提前这将不胜感激。

It would be grateful if anyone suggest me a way to get rid of this bug.Thanks in advance.

推荐答案

您需要提供连续的步骤，你的数据在后台线程加载。当你选择一个页面，你有两个选择。

You need to provide the sequential steps as your data is being loaded in the background thread. When you select a page, you have two options.

1。启动是同步凌空通话这个调用后更新微调适配器

1. Initiate either a Synchronous Volley calland update the spinner adapter after this call

RequestFuture<JSONObject> future = RequestFuture.newFuture();
JsonObjectRequest request = new JsonObjectRequest(URL, null, future, future);
requestQueue.add(request);

try {
  JSONObject response = future.get(); // this will block (forever)
  ArrayList<String> some_items = response.getStringArray();
  //update the spinner with new items

} catch (InterruptedException e) {
  // exception handling
} catch (ExecutionException e) {
  // exception handling
}

2。注册广播接收器在活动然后 sendBroadcast 到<一个code> LocalBroadcastManager 在 VolleyResponse 。在广播接收器的更新的onReceive微调项

2. Register a BroadcastReceiver in your Activity and then sendBroadcast through LocalBroadcastManager on VolleyResponse. and update the spinner items in onReceive of BroadcastReceiver

希望这有助于。

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