Android 设置适配器后出现RecyclerView错误

我得到

当我想显示包含RecyclerView的片段时。 我不知道在哪里编辑我的代码，我搜索了这个错误，发现了一些建议，比如在

RecyclerView

上禁用动画，但在我的情况下它不起作用

以下是片段的代码：

package com.example.event.fragments

import android.os.Bundle
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.lifecycle.ViewModelProviders
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.example.event.adapters.NotificationsAdapter
import com.example.event.databinding.FragmentNotificationsBinding
import com.example.event.model.Notification
import com.example.event.viewmodel.NotificationViewModel
import com.faltenreich.skeletonlayout.Skeleton
import com.faltenreich.skeletonlayout.createSkeleton

class NotificationsFragment : Fragment() {

    private lateinit var notificationsFragmentBinding: FragmentNotificationsBinding
    private lateinit var notificationViewModel: NotificationViewModel
    private lateinit var recyclerViewNotificationsSkeleton: Skeleton

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        notificationsFragmentBinding = FragmentNotificationsBinding.inflate(layoutInflater)
        notificationViewModel =
            activity?.run { ViewModelProviders.of(this).get(NotificationViewModel::class.java) }
                ?: throw Exception("Invalid Activity")
        recyclerViewNotificationsSkeleton =
            notificationsFragmentBinding.notificationsRecyclerView.createSkeleton(showShimmer = true)
        recyclerViewNotificationsSkeleton.showSkeleton()

        return notificationsFragmentBinding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        val notifications = arguments?.get("notifications") as List<Notification>
        notificationsFragmentBinding.notificationsRecyclerView.layoutManager =
            LinearLayoutManager(this.activity, RecyclerView.VERTICAL, false)
        notificationsFragmentBinding.notificationsRecyclerView.adapter =
            NotificationsAdapter(notifications)
        recyclerViewNotificationsSkeleton.showOriginal()
    }
}

---

有人能帮我吗？提前感谢

我认为你应该使用

findViewById（）

来使用

recyclerView

而不是使用数据绑定？是的，很遗憾，尝试一下，然后再次运行相同的错误。请发布整个堆栈跟踪

package com.example.event.fragments

import android.os.Bundle
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.lifecycle.ViewModelProviders
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.example.event.adapters.NotificationsAdapter
import com.example.event.databinding.FragmentNotificationsBinding
import com.example.event.model.Notification
import com.example.event.viewmodel.NotificationViewModel
import com.faltenreich.skeletonlayout.Skeleton
import com.faltenreich.skeletonlayout.createSkeleton

class NotificationsFragment : Fragment() {

    private lateinit var notificationsFragmentBinding: FragmentNotificationsBinding
    private lateinit var notificationViewModel: NotificationViewModel
    private lateinit var recyclerViewNotificationsSkeleton: Skeleton

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        notificationsFragmentBinding = FragmentNotificationsBinding.inflate(layoutInflater)
        notificationViewModel =
            activity?.run { ViewModelProviders.of(this).get(NotificationViewModel::class.java) }
                ?: throw Exception("Invalid Activity")
        recyclerViewNotificationsSkeleton =
            notificationsFragmentBinding.notificationsRecyclerView.createSkeleton(showShimmer = true)
        recyclerViewNotificationsSkeleton.showSkeleton()

        return notificationsFragmentBinding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        val notifications = arguments?.get("notifications") as List<Notification>
        notificationsFragmentBinding.notificationsRecyclerView.layoutManager =
            LinearLayoutManager(this.activity, RecyclerView.VERTICAL, false)
        notificationsFragmentBinding.notificationsRecyclerView.adapter =
            NotificationsAdapter(notifications)
        recyclerViewNotificationsSkeleton.showOriginal()
    }
}

package com.example.event.adapters

import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.example.event.R
import com.example.event.model.Notification
import com.squareup.picasso.Picasso
import kotlinx.android.synthetic.main.item_notification.view.*


class NotificationsAdapter(private val notifications: List<Notification>) :
    RecyclerView.Adapter<NotificationsAdapter.ViewHolder>() {

    private val notificationActionMessage = hashMapOf(
        "partecipate" to "parteciperà al tuo evento",
        "interested" to "è interessato al tuo evento",
        "comment" to "ha commentato il tuo evento"
    )

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val view: View =
            LayoutInflater.from(parent.context)
                .inflate(R.layout.item_notification, parent, false)
        return ViewHolder(view)
    }

    override fun getItemCount() = notifications.size

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        val notification: Notification = notifications[position]
        Picasso
            .get()
            .load(notification.senderImage)
            .fit()
            .centerInside()
            .into(holder.senderProfileImage)
        holder.senderUsername.text = notification.sender
        holder.eventName.text = notification.eventName
        holder.notificationAction.text = notificationActionMessage[notification.notificationAction]
    }

    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val senderUsername: TextView = itemView.senderTextView
        val senderProfileImage: ImageView = itemView.senderProfileImage
        val notificationAction: TextView = itemView.notificationActionTextView
        val eventName: TextView = itemView.eventNameTextView
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

            <androidx.recyclerview.widget.RecyclerView
                android:id="@+id/notificationsRecyclerView"
                android:layout_width="match_parent"
                android:layout_height="match_parent" />
        </LinearLayout>
    </ScrollView>

</androidx.constraintlayout.widget.ConstraintLayout>

2020-02-05 11:27:31.924 868-868/com.example.event E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.event, PID: 868
    java.lang.NullPointerException: Attempt to invoke virtual method 'boolean androidx.recyclerview.widget.RecyclerView$ViewHolder.shouldIgnore()' on a null object reference
        at androidx.recyclerview.widget.RecyclerView.findMinMaxChildLayoutPositions(RecyclerView.java:4311)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep1(RecyclerView.java:4045)
        at androidx.recyclerview.widget.RecyclerView.onMeasure(RecyclerView.java:3534)
        at android.view.View.measure(View.java:24530)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6828)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
        at android.view.View.measure(View.java:24530)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6828)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1552)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:842)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:721)
        at android.view.View.measure(View.java:24530)
        at android.widget.ScrollView.measureChildWithMargins(ScrollView.java:1414)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
        at android.widget.ScrollView.onMeasure(ScrollView.java:452)
        at android.view.View.measure(View.java:24530)
        at androidx.constraintlayout.widget.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:1227)
        at androidx.constraintlayout.widget.ConstraintLayout.onMeasure(ConstraintLayout.java:1572)
        at android.view.View.measure(View.java:24530)
        at androidx.constraintlayout.widget.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:1227)
        at androidx.constraintlayout.widget.ConstraintLayout.onMeasure(ConstraintLayout.java:1572)
        at android.view.View.measure(View.java:24530)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6828)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
        at androidx.appcompat.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
        at android.view.View.measure(View.java:24530)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6828)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1552)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:842)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:721)
        at android.view.View.measure(View.java:24530)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6828)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
        at android.view.View.measure(View.java:24530)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6828)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1552)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:842)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:721)
        at android.view.View.measure(View.java:24530)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6828)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
        at com.android.internal.policy.DecorView.onMeasure(DecorView.java:742)
        at android.view.View.measure(View.java:24530)
        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:3006)
        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1833)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2122)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1721)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7598)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:966)
        at android.view.Choreographer.doCallbacks(Choreographer.java:790)
        at android.view.Choreographer.doFrame(Choreographer.java:725)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:951)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:214)
2020-02-05 11:27:31.940 868-868/com.example.event E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)