java.lang.IllegalStateException：键 f0 的片段不再存在：索引 1

Question

我在一个活动中有几个片段。完成一些过程后，我使用以下代码关闭片段。

if (getActivity().getSupportFragmentManager().getBackStackEntryCount() > 0) {
                        getActivity().getSupportFragmentManager().popBackStackImmediate();
}

但是在线 popBackStackImmediate() 抛出错误

    Process: com.TestProject.testpro, PID: 17966
 java.lang.IllegalStateException: Fragment no longer exists for key f0: index 1
     at android.support.v4.app.FragmentManagerImpl.getFragment(FragmentManager.java:879)
     at android.support.v4.app.FragmentStatePagerAdapter.restoreState(FragmentStatePagerAdapter.java:215)
     at android.support.v4.view.ViewPager.onRestoreInstanceState(ViewPager.java:1481)
     at android.view.View.dispatchRestoreInstanceState(View.java:14746)
     at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3121)
     at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3127)
     at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3127)
     at android.view.View.restoreHierarchyState(View.java:14724)
     at android.support.v4.app.Fragment.restoreViewState(Fragment.java:475)
     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1329)
     at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1528)
     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1595)
     at android.support.v4.app.BackStackRecord.executePopOps(BackStackRecord.java:807)
     at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2360)
     at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2149)
     at android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps(FragmentManager.java:2103)
     at android.support.v4.app.FragmentManagerImpl.popBackStackImmediate(FragmentManager.java:823)
     at android.support.v4.app.FragmentManagerImpl.popBackStackImmediate(FragmentManager.java:776)
     at com.TestProject.testpro.application.fragments.WFMUpgradeToAffinityFragmentAN$WFMStoreProfileIdReceiver.onReceive(WFMUpgradeToAffinityFragmentAN.java:1064)
     at android.support.v4.content.LocalBroadcastManager.executePendingBroadcasts(LocalBroadcastManager.java:297)
     at android.support.v4.content.LocalBroadcastManager.access$000(LocalBroadcastManager.java:46)
     at android.support.v4.content.LocalBroadcastManager$1.handleMessage(LocalBroadcastManager.java:116)
     at android.os.Handler.dispatchMessage(Handler.java:102)
     at android.os.Looper.loop(Looper.java:148)
     at android.app.ActivityThread.main(ActivityThread.java:5417)
     at java.lang.reflect.Method.invoke(Native Method)
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

没有其他崩溃关闭片段。我找不到这个问题的确切解决方案。请帮我解决这个问题。

编辑：

我正在使用下面的函数来调用片段。

void showContentFragment(Fragment newFragment, String backStackName) {
    //Log.e(TAG, "showContentFragment- " + "BackstackName: "+ backStackName);
    FragmentManager mFragmentManager = getActivity().getSupportFragmentManager();
    if (newFragment != null) {
        //updateNavigation(backStackName);
        FragmentTransaction ft = mFragmentManager.beginTransaction();
        ft.replace(R.id.fragment_container, newFragment);
        if (backStackName != null && !backStackName.isEmpty()) {
            ft.addToBackStack(backStackName);
        }

        ft.commit();
    }
}

Answer 1

对于 ViewPager2 只需使用 viewPager.setSaveEnabled(false);

Answer 2

请按照以下步骤添加活动中的片段

 getSupportFragmentManager().beginTransaction()
                .replace(R.id.frame, yourFragment, yourFragment.class.getSimpleName()).addToBackStack(yourFragment.class.getSimpleName())
                .commit();

popBackStack()使用此代码从您的片段调用

    if (getFragmentManager().getBackStackEntryCount() > 0) {
                        getFragmentManager().popBackStack();
}

确保您导入正确的片段类

import android.support.v4.app.Fragment;