不要在RecyclerView中显示来自Firebase的对象

Question

我从Firebase获取事件列表，并使用FirebaseUI填充RecyclerView。一个事件对象具有一个名为Attended的字段，该字段为true或false。

如何隐藏/删除出席字段中值为false的对象？我知道最好的方法是将所有参加的活动分开存储，然后从中填充RecyclerView，但是由于活动的结构，这是不可能的。

编辑：

    2019-04-02 12:32:51.126 7807-7807/com.example.concertmate E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.concertmate, PID: 7807
    java.lang.IllegalArgumentException: When using orderByPriority(), values provided to startAt(), endAt(), or equalTo() must be valid priorities.
        at com.google.firebase.database.Query.validateQueryEndpoints(com.google.firebase:firebase-database@@16.0.6:106)
        at com.google.firebase.database.Query.startAt(com.google.firebase:firebase-database@@16.0.6:377)
        at com.google.firebase.database.Query.startAt(com.google.firebase:firebase-database@@16.0.6:363)
        at com.google.firebase.database.Query.equalTo(com.google.firebase:firebase-database@@16.0.6:568)
        at com.example.concertmate.Fragments.ConcertFragment.onCreateView(ConcertFragment.java:115)
        at android.support.v4.app.Fragment.performCreateView(Fragment.java:2439)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1460)
        at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1784)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1852)
        at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:802)
        at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2625)
        at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2411)
        at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366)
        at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2243)
        at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:654)
        at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:146)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:1244)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:1092)
        at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1622)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:733)
        at android.support.design.widget.HeaderScrollingViewBehavior.onMeasureChild(HeaderScrollingViewBehavior.java:95)
        at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onMeasureChild(AppBarLayout.java:1556)
        at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:803)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.view.View.measure(View.java:23355)
        at android.support.constraint.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:1227)
        at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:1572)
        at android.view.View.measure(View.java:23355)
        at android.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:1119)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1535)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:825)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:704)
        at android.view.View.measure(View.java:23355)
2019-04-02 12:32:51.126 7807-7807/com.example.concertmate E/AndroidRuntime:     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at com.android.internal.policy.DecorView.onMeasure(DecorView.java:717)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2917)
        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1747)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2040)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1635)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7795)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1172)
        at android.view.Choreographer.doCallbacks(Choreographer.java:984)
        at android.view.Choreographer.doFrame(Choreographer.java:809)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1158)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6863)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:537)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
2019-04-02 12:32:51.127 7807-7807/com.example.concertmate E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.concertmate, PID: 7807
    java.lang.IllegalArgumentException: When using orderByPriority(), values provided to startAt(), endAt(), or equalTo() must be valid priorities.
        at com.google.firebase.database.Query.validateQueryEndpoints(com.google.firebase:firebase-database@@16.0.6:106)
        at com.google.firebase.database.Query.startAt(com.google.firebase:firebase-database@@16.0.6:377)
        at com.google.firebase.database.Query.startAt(com.google.firebase:firebase-database@@16.0.6:363)
        at com.google.firebase.database.Query.equalTo(com.google.firebase:firebase-database@@16.0.6:568)
        at com.example.concertmate.Fragments.ConcertFragment.onCreateView(ConcertFragment.java:115)
        at android.support.v4.app.Fragment.performCreateView(Fragment.java:2439)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1460)
        at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1784)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1852)
        at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:802)
        at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2625)
        at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2411)
        at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366)
        at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2243)
        at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:654)
        at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:146)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:1244)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:1092)
        at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1622)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:733)
        at android.support.design.widget.HeaderScrollingViewBehavior.onMeasureChild(HeaderScrollingViewBehavior.java:95)
        at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onMeasureChild(AppBarLayout.java:1556)
        at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:803)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.view.View.measure(View.java:23355)
        at android.support.constraint.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:1227)
        at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:1572)
        at android.view.View.measure(View.java:23355)
        at android.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:1119)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1535)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:825)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:704)
        at android.view.View.measure(View.java:23355)
2019-04-02 12:32:51.127 7807-7807/com.example.concertmate E/AndroidRuntime:     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6758)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at com.android.internal.policy.DecorView.onMeasure(DecorView.java:717)
        at android.view.View.measure(View.java:23355)
        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2917)
        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1747)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2040)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1635)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7795)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1172)
        at android.view.Choreographer.doCallbacks(Choreographer.java:984)
        at android.view.Choreographer.doFrame(Choreographer.java:809)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1158)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6863)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:537)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

这是我尝试对查询使用equalTo时遇到的错误。

 query = FirebaseDatabase.getInstance()
                .getReference()
                .child("concert").child(auth.getCurrentUser().getUid()).equalTo(true,"favorite");

这是数据库结构的图像。 firebase structure

它是concert -> user uuid -> event uuid。

Answer 1

在您的recyclerView视图中的onBind内部，您可以检查该变量是true还是false。如果是真的，则可以移至下一个对象，而无需设置任何值。

如果您提供一些示例，您将尝试什么，以及如何设置recyclerView，这样我就可以给出一些实际的示例，这将很有帮助。

另一种选择是以某种方式查询数据，该方式将仅检索为true的对象或仅为false的对象。