无论何时在视图寻呼机中更改选项卡时如何更新列表 [英] How to update the List whenever the tabs are changing in view pager

问题描述

在我的应用程序中，我正在使用使用视图寻呼机的导航选项卡.我已经能够使用发布在以下位置的代码成功绘制标签:

https://github.com/codepath/android_guides/wiki/Sliding-Tabs-with-PagerSlidingTabStrip

在这里，我使用了滑动选项卡和视图寻呼机来获取导航选项卡.一切正常，但是当我移动到另一个选项卡时，列表没有得到更新.OnResume() 被调用，即使对象列表变量也在调试时得到更新，但视觉列表没有得到更新.

这里是一些代码片段:

<块引用>

对于 Tab1 :在我的情况下是 ACTIVE 选项卡

 @Override公共无效 onResume() {超级.onResume();if(!internetUtil.isConnectedToInternet(getActivity())){mSwipeRefreshLayout.setEnabled(false);}别的{mSwipeRefreshLayout.setEnabled(true);新的 GetUsersFromServerTask().execute();//这里我进行网络调用}}

<块引用>

在 Tab2 上:这是存档选项卡

 @Override公共无效 onResume() {超级.onResume();新的 GetUsersArchivedFromServerTask().execute();//网络调用}

在 MainActivity 中:

公共类 MaterialTab 扩展 FragmentActivity {@覆盖protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.material_main_sample);ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);viewPager.setAdapter(new SampleFragmentPagerAdapter(getSupportFragmentManager()));PagerSlidingTabStrip tabsStrip = (PagerSlidingTabStrip) findViewById(R.id.tabs);tabsStrip.setViewPager(viewPager);tabsStrip.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {@覆盖公共无效 onPageSelected(int position) {如果(位置 == 0){ActiveFragment activeFragment = new ActiveFragment();最终 FragmentTransaction ft = getSupportFragmentManager().beginTransaction();ft.detach(activeFragment);ft.attach(activeFragment);ft.commit();} 如果(位置 == 1){ArchiveFragment archiveFragment = new ArchiveFragment();最终 FragmentTransaction ft = getSupportFragmentManager().beginTransaction();ft.detach(archiveFragment);ft.attach(archiveFragment);ft.commit();}}});}}

另外，当我执行 SwipeRefresh 时，列表正在更新.我现在完全困惑为什么会出现这种行为.当我滑动选项卡时，会调用相同的方法并且列表没有更新，但是当我执行 SwipeRefresh 时，它会更新.

这是活动片段:

公共类 ActiveFragment 扩展 Fragment {公共无效更新片段(){新的 GetUsersArchivedFromServerTask().execute();}公共类 GetUsersArchivedFromServerTask 扩展 AsyncTask<User, Void, String>{@覆盖受保护的字符串doInBackground(装运...帕尔马斯){//Log.d(TAG, String.valueOf(shipmentDbHandler.getAllActiveShipments().size()));_userList1 = userDbHandler.getAllActiveUserByToday(DateTimeUtil.getCurrentTime());返回 "";}@覆盖受保护的无效onPreExecute(){super.onPreExecute();}@覆盖受保护的无效 onPostExecute(字符串 str){//在列表加载了一组新数据后，将刷新监听器设置为 falseif (mSwipeRefreshLayout.isRefreshing()) {mSwipeRefreshLayout.setRefreshing(false);}if(_userList1.size() == 0){ViewGroup parentOne = (ViewGroup) viewOne.getParent();if(parentOne != null){parentOne.removeView(viewOne);}}if(_shipmentList1.size() > 0 ){mShipmentAdapter = new ShipmentAdapter(getActivity(),_userList1,1);shipListView1.setAdapter(mShipmentAdapter);setListViewHeightBasedOnChildren(shipmentListView1);ViewGroup parentOne = (ViewGroup) viewOne.getParent();如果(parentOne == null){mainLayoutOne.addView(viewOne);}mShipmentAdapter.notifyDataSetChanged();}mSwipeRefreshLayout.setClickable(true);}}}

解决方案

请使用 FragmentStatePagerAdapter.

In my app i am using navigation tab using view pager. I have able to successfully drawn the tabs using the code posted on:

https://github.com/codepath/android_guides/wiki/Sliding-Tabs-with-PagerSlidingTabStrip

Here i have used the Sliding tab and view pager both to get the navigation tabs.Everything is working fine but the list are not getting updated when i am moving to the other tab. OnResume() is getting called even the Object list variable is also getting updated while debugging but visually list is not getting updated.

Here i am some snippets of the code:

For Tab1 : which in my case is ACTIVE tab

 @Override
    public void onResume() {
        super.onResume();

        if(!internetUtil.isConnectedToInternet(getActivity())){
            mSwipeRefreshLayout.setEnabled(false);
        }else{
            mSwipeRefreshLayout.setEnabled(true);
            new GetUsersFromServerTask().execute();  // Here i am making the network calls 
        }
}

On Tab2 : Which is Archive tab

 @Override
    public void onResume() {
        super.onResume();
        new GetUsersArchivedFromServerTask().execute(); // Network calls
    }

In MainActivity:

public class MaterialTab extends FragmentActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.material_main_sample);
        ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
        viewPager.setAdapter(new SampleFragmentPagerAdapter(getSupportFragmentManager()));
        PagerSlidingTabStrip tabsStrip = (PagerSlidingTabStrip) findViewById(R.id.tabs);
        tabsStrip.setViewPager(viewPager);
        tabsStrip.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                if(position == 0){
                   ActiveFragment activeFragment = new ActiveFragment();
                    final FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
                    ft.detach(activeFragment);
                    ft.attach(activeFragment);
                    ft.commit();
                } if(position == 1){
                    ArchiveFragment archiveFragment = new ArchiveFragment();
                    final FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
                    ft.detach(archiveFragment);
                    ft.attach(archiveFragment);
                    ft.commit();
                }
            }
        });
    }
}

Also the thing is when i am doing SwipeRefresh then the List is getting updated. I am now totally confused why this behaviour. When i am swiping the tab the same methods are getting called and thelist is not getting updated but when I am doing SwipeRefresh it's getting Updated.

This is the Active Fragment:

public class ActiveFragment extends Fragment {

public void updateFragment(){
        new GetUsersArchivedFromServerTask().execute();
    }

 public class GetUsersArchivedFromServerTask extends AsyncTask<User, Void, String> {
        @Override
        protected String doInBackground(Shipment... parmas) {
            // Log.d(TAG, String.valueOf(shipmentDbHandler.getAllActiveShipments().size()));
            _userList1 = userDbHandler.getAllActiveUserByToday(DateTimeUtil.getCurrentTime());
            return "";
        }

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

        @Override
        protected void onPostExecute(String str) {
            // Set the refresh Listener to false after the list has been loaded with new set of data
            if (mSwipeRefreshLayout.isRefreshing()) {
                mSwipeRefreshLayout.setRefreshing(false);
            }

            if(_userList1.size() == 0){
                ViewGroup parentOne = (ViewGroup) viewOne.getParent();
                if(parentOne != null){
                    parentOne.removeView(viewOne);
                }
            }

            if(_shipmentList1.size() > 0 ){
                mShipmentAdapter = new ShipmentAdapter(getActivity(),_userList1,1); 
                shipmentListView1.setAdapter(mShipmentAdapter);
                setListViewHeightBasedOnChildren(shipmentListView1);
                ViewGroup parentOne = (ViewGroup) viewOne.getParent();
                if(parentOne == null){
                    mainLayoutOne.addView(viewOne);
                }

                mShipmentAdapter.notifyDataSetChanged();
            }
            mSwipeRefreshLayout.setClickable(true);
        }
    }
}   

解决方案

PLease use FragmentStatePagerAdapter for that.

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