Firebase Firestore addSnapshotListener（）可能导致“FragmentManager正在执行事务”错误

Question

我最近发现了一个项目，我在一段时间以前正在进行的一个项目中更新了依赖项，与此事件相关，我将FireStore的依赖项(com.google.firebase:firebase-firestore)从17.1.5更新到了最新的18.2.0。因为这次更新，现在我的app突然抛出如下错误：

IllegalStateException：FragmentManager已经在执行事务

在片段的OnActivityCreated方法中调用AddSnapshotListener()时。（由于错误是关于fragmentmanager的，我认为这可能是相关的）

具体代码如下：

docRef.collection(COLLECTION_PATH).addSnapshotListener(Objects.requireNonNull(getActivity()), (queryDocumentSnapshots, e) -> {
      //other stuff to do after detecting collection change
});

当我将依赖关系恢复到原来的依赖关系时，错误就消失了。我猜Firestore中的某种行为改变破坏了我的代码，但我仍然不确定它到底是什么，以及如何修复它。

下面是详细的错误堆栈跟踪：

java.lang.IllegalStateException: FragmentManager is already executing transactions
        at androidx.fragment.app.FragmentManagerImpl.ensureExecReady(FragmentManagerImpl.java:1657)
        at androidx.fragment.app.FragmentManagerImpl.execPendingActions(FragmentManagerImpl.java:1717)
        at androidx.fragment.app.FragmentManagerImpl.executePendingTransactions(FragmentManagerImpl.java:228)
        at com.google.firebase.firestore.util.ListenerRegistrationImpl.lambda$onFragmentActivityStopCallOnce$1(com.google.firebase:firebase-firestore@@18.2.0:190)
        at com.google.firebase.firestore.util.ListenerRegistrationImpl$$Lambda$2.run(Unknown Source:4)
        at android.app.Activity.runOnUiThread(Activity.java:6282)
        at com.google.firebase.firestore.util.ListenerRegistrationImpl.onFragmentActivityStopCallOnce(com.google.firebase:firebase-firestore@@18.2.0:174)
        at com.google.firebase.firestore.util.ListenerRegistrationImpl.<init>(com.google.firebase:firebase-firestore@@18.2.0:209)
        at com.google.firebase.firestore.Query.addSnapshotListenerInternal(com.google.firebase:firebase-firestore@@18.2.0:917)
        at com.google.firebase.firestore.Query.addSnapshotListener(com.google.firebase:firebase-firestore@@18.2.0:882)
        at com.google.firebase.firestore.Query.addSnapshotListener(com.google.firebase:firebase-firestore@@18.2.0:823)
        ... [My app's call to addSnapshotListener] ...
at androidx.fragment.app.Fragment.performActivityCreated(Fragment.java:2565)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:907)
        at androidx.fragment.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManagerImpl.java:1235)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:1301)
        at androidx.fragment.app.BackStackRecord.executeOps(BackStackRecord.java:710)
        at androidx.fragment.app.FragmentManagerImpl.executeOps(FragmentManagerImpl.java:2071)
        at androidx.fragment.app.FragmentManagerImpl.executeOpsTogether(FragmentManagerImpl.java:1861)
        at androidx.fragment.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManagerImpl.java:1816)
        at androidx.fragment.app.FragmentManagerImpl.execSingleAction(FragmentManagerImpl.java:1693)
        at androidx.fragment.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:560)
        at androidx.fragment.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:148)
        at androidx.viewpager.widget.ViewPager.populate(ViewPager.java:1244)
        at androidx.viewpager.widget.ViewPager.populate(ViewPager.java:1092)
        at androidx.viewpager.widget.ViewPager.onMeasure(ViewPager.java:1622)
        at android.view.View.measure(View.java:23169)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
        at androidx.coordinatorlayout.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:743)
        at androidx.coordinatorlayout.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:815)
        at android.view.View.measure(View.java:23169)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at androidx.appcompat.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
        at android.view.View.measure(View.java:23169)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
        at androidx.appcompat.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:403)
        at android.view.View.measure(View.java:23169)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.view.View.measure(View.java:23169)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749)

更新：刚刚更新到19.0.0，错误仍然存在。

Answer 1

删除AddSnapshotListener中的getActivity（）。使用listener.remove on onPause（）处理侦听器分离。

    Query query = db.collection("cities");
ListenerRegistration registration = query.addSnapshotListener(
        new EventListener<QuerySnapshot>() {
            // ...
        });

// ...

// Stop listening to changes
registration.remove();