使用方法setOffscreenPageLimit()后，FragmentManager已经在执行事务 [英] FragmentManager is already executing transactions after using method setOffscreenPageLimit()
问题描述
我有一个带有多个片段的导航抽屉，其中一个是带有两个recyclerview片段的布局，在导航抽屉片段之间切换后，RecyclerView项消失了，我找到了一个解决方案，需要使用setOffscreenPageLimit()方法ViewPager，但它给了我问题标题中提到的错误
i have a navigation drawer with a number of fragments and one of them is a tablayout with two recyclerview fragments , the RecyclerView items disappear after switching between navigation drawer fragments , i found a solution that i need to use method setOffscreenPageLimit() with the ViewPager but it gives me the bug that is mentioned in the question title
这是我的日志
java.lang.IllegalStateException: FragmentManager is already executing transactions
at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:1626)
at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:679)
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:143)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1240)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1088)
at android.support.v4.view.ViewPager.setOffscreenPageLimit(ViewPager.java:852)
at com.amir.ahmed.EELUStudentUnion.SelectionFragment.setupViewPager(SelectionFragment.java:59)
at com.amir.ahmed.EELUStudentUnion.SelectionFragment.onActivityCreated(SelectionFragment.java:40)
at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:2089)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1133)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1290)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:801)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1677)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:536)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7225)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
这是选项卡布局片段代码
an that is the tab layout fragment code
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
viewPager = (ViewPager) getActivity().findViewById(R.id.viewpager);
setupViewPager(viewPager);
viewPager.setOffscreenPageLimit(2);
tabLayout = (TabLayout) getActivity().findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
setupTabIcons();
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getFragmentManager());
adapter.addFrag(new Courses(), "IT");
adapter.addFrag(new CoursesBussiness(), "Business");
viewPager.setAdapter(adapter);
}
推荐答案
我和您遇到了类似的问题，经过几个小时的研究，我发现了这个问题. 如果您的ViewPager是在Fragment内创建的，则需要对FragmentPagerAdapter使用getChildFragmentManager()，而不是getFragmentManager().
I encountered the similar issue as you, after several hours research, I found the issue. If your ViewPager is created inside the Fragment, you need to use getChildFragmentManager() for the FragmentPagerAdapter, rather than getFragmentManager().
因此，您的setupViewPager()方法应如下所示.
So your setupViewPager() method should look like this.
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getChildFragmentManager());
adapter.addFrag(new Courses(), "IT");
adapter.addFrag(new CoursesBussiness(), "Business");
viewPager.setAdapter(adapter);
}
此问题的根本原因是您将Fragments嵌入Fragment中，这就是为什么它将引发异常的原因.
The root cause of the issue is you embeded Fragments inside the Fragment, that's why it will throw the exception.
java.lang.IllegalStateException: FragmentManager is already executing transactions
根据Google的文档:
According to the Google's docs:
您现在可以将片段嵌入片段中.这对于 您想放置动态且可重复使用的各种情况 将UI组件转换为本身是动态的， 可重复使用的.例如，如果您使用ViewPager创建片段， 向左和向右滑动并占用屏幕的大部分空间，您 现在可以将片段插入每个片段页面.要嵌套一个片段， 只需在您要在其中的片段上调用getChildFragmentManager() 要添加一个片段.这将返回一个FragmentManager，您可以 像平常一样使用顶级活动来创建 零碎交易.
You can now embed fragments inside fragments. This is useful for a variety of situations in which you want to place dynamic and re-usable UI components into a UI component that is itself dynamic and re-usable. For example, if you use ViewPager to create fragments that swipe left and right and consume a majority of the screen space, you can now insert fragments into each fragment page. To nest a fragment, simply call getChildFragmentManager() on the Fragment in which you want to add a fragment. This returns a FragmentManager that you can use like you normally do from the top-level activity to create fragment transactions.
这篇关于使用方法setOffscreenPageLimit()后，FragmentManager已经在执行事务的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
