Wie lasse ich WRAP_CONTENT in einer RecyclerView funktionieren?

Ich habe eine DialogFragment, die eine enthält RecyclerView(eine Liste von Karten).

Darin RecyclerViewbefinden sich eine oder mehrere CardViews, die eine beliebige Höhe haben können.

Ich möchte diesem DialogFragmentdie richtige Höhe geben, basierend auf den CardViewsdarin enthaltenen.

Normalerweise wäre dies einfach, ich setzen würde wrap_contentauf das RecyclerViewso.

<android.support.v7.widget.RecyclerView ...
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/recycler_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"   
    android:clickable="true"   
    android:scrollbars="vertical" >

</android.support.v7.widget.RecyclerView>

Da ich ein benutze RecyclerViewdas nicht funktioniert siehe:

https://issuetracker.google.com/issues/37001674

und

Die Höhe der verschachtelten Recycler-Ansicht umschließt den Inhalt nicht

Auf beiden Seiten wird empfohlen, diese zu erweitern LinearLayoutManagerund zu überschreibenonMeasure()

Ich habe zuerst den LayoutManager verwendet , den jemand im ersten Link angegeben hat:

public static class WrappingLayoutManager extends LinearLayoutManager {

        public WrappingLayoutManager(Context context) {
            super(context);
        }

        private int[] mMeasuredDimension = new int[2];

        @Override
        public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state,
                              int widthSpec, int heightSpec) {
            final int widthMode = View.MeasureSpec.getMode(widthSpec);
            final int heightMode = View.MeasureSpec.getMode(heightSpec);
            final int widthSize = View.MeasureSpec.getSize(widthSpec);
            final int heightSize = View.MeasureSpec.getSize(heightSpec);

            measureScrapChild(recycler, 0,
                    View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED),
                    View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED),
                    mMeasuredDimension);

            int width = mMeasuredDimension[0];
            int height = mMeasuredDimension[1];

            switch (widthMode) {
                case View.MeasureSpec.EXACTLY:
                case View.MeasureSpec.AT_MOST:
                    width = widthSize;
                    break;
                case View.MeasureSpec.UNSPECIFIED:
            }

            switch (heightMode) {
                case View.MeasureSpec.EXACTLY:
                case View.MeasureSpec.AT_MOST:
                    height = heightSize;
                    break;
                case View.MeasureSpec.UNSPECIFIED:
            }

            setMeasuredDimension(width, height);
        }

        private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
                                       int heightSpec, int[] measuredDimension) {
            View view = recycler.getViewForPosition(position);
            if (view != null) {
                RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
                int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
                        getPaddingLeft() + getPaddingRight(), p.width);
                int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                        getPaddingTop() + getPaddingBottom(), p.height);
                view.measure(childWidthSpec, childHeightSpec);
                measuredDimension[0] = view.getMeasuredWidth();
                measuredDimension[1] = view.getMeasuredHeight();
                recycler.recycleView(view);
            }
        }
    }

Dies funktionierte jedoch nicht, weil

heightSize = View.MeasureSpec.getSize(heightSpec);

Gibt einen sehr großen Wert zurück, der in Beziehung zu stehen scheint match_parent.

Durch Kommentieren height = heightSize;(im zweiten Schalterfall) gelang es mir, die Höhe zum Laufen zu bringen, aber nur, wenn ein TextViewKind im Inneren CardViewkeinen eigenen Text umschließt (ein langer Satz).

Sobald TextViewdies seinen eigenen Text umschließt, sollte die Höhe erhöht werden, aber dies ist nicht der Fall. Die Höhe für diesen langen Satz wurde als einzelne Zeile berechnet, nicht als umbrochene Zeile (2 oder mehr).

Irgendwelche Ratschläge, wie ich das verbessern soll, LayoutManagerdamit ich damit RecyclerViewarbeite WRAP_CONTENT?

Bearbeiten: Dieser Layout-Manager funktioniert möglicherweise für die meisten Benutzer, hat jedoch weiterhin Probleme beim Scrollen und Berechnen der Höhe beim Umschließen von Textansichten

public class MyLinearLayoutManager extends LinearLayoutManager {

public MyLinearLayoutManager(Context context, int orientation, boolean reverseLayout)    {
    super(context, orientation, reverseLayout);
}

private int[] mMeasuredDimension = new int[2];

@Override
public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state,
                      int widthSpec, int heightSpec) {
    final int widthMode = View.MeasureSpec.getMode(widthSpec);
    final int heightMode = View.MeasureSpec.getMode(heightSpec);
    final int widthSize = View.MeasureSpec.getSize(widthSpec);
    final int heightSize = View.MeasureSpec.getSize(heightSpec);
    int width = 0;
    int height = 0;
    for (int i = 0; i < getItemCount(); i++) {
        measureScrapChild(recycler, i,
                View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                mMeasuredDimension);

        if (getOrientation() == HORIZONTAL) {
            width = width + mMeasuredDimension[0];
            if (i == 0) {
                height = mMeasuredDimension[1];
            }
        } else {
            height = height + mMeasuredDimension[1];
            if (i == 0) {
                width = mMeasuredDimension[0];
            }
        }
    }
    switch (widthMode) {
        case View.MeasureSpec.EXACTLY:
            width = widthSize;
        case View.MeasureSpec.AT_MOST:
        case View.MeasureSpec.UNSPECIFIED:
    }

    switch (heightMode) {
        case View.MeasureSpec.EXACTLY:
            height = heightSize;
        case View.MeasureSpec.AT_MOST:
        case View.MeasureSpec.UNSPECIFIED:
    }

    setMeasuredDimension(width, height);
}

    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
                                   int heightSpec, int[] measuredDimension) {
        View view = recycler.getViewForPosition(position);
        if (view != null) {
            RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
            int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
                    getPaddingLeft() + getPaddingRight(), p.width);
            int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                    getPaddingTop() + getPaddingBottom(), p.height);
            view.measure(childWidthSpec, childHeightSpec);
            measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;
            measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin;
            recycler.recycleView(view);
        }
    }
}

Ab dem Update der Android Support Library 23.2.1 sollten alle WRAP_CONTENT ordnungsgemäß funktionieren.

Bitte aktualisieren Sie die Version einer Bibliothek in der gradleDatei ODER auf weitere:

compile 'com.android.support:recyclerview-v7:23.2.1'

Einige Probleme wurden behoben, z. B. Fehler im Zusammenhang mit verschiedenen Methoden für Messspezifikationen behoben

Überprüfen Sie http://developer.android.com/tools/support-library/features.html#v7-recyclerview

Sie können den Versionsverlauf der Support Library überprüfen

UPDATE 05.07.2019

Wenn Sie RecyclerViewin a verwenden ScrollView, wechseln Sie einfach ScrollViewzu androidx.core.widget.NestedScrollView. Innerhalb dieser Ansicht gibt es keine Notwendigkeit zu packen RecyclerViewinnen ein RelativeLayout.

<androidx.core.widget.NestedScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent">

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

        <!-- other views -->

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/list"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <!-- other views -->

    </LinearLayout>

</androidx.core.widget.NestedScrollView>

Endlich die Lösung für dieses Problem gefunden.

Alles was Sie tun müssen, ist das RecyclerViewin ein zu wickeln RelativeLayout. Vielleicht gibt es andere Ansichten, die auch funktionieren können.

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</RelativeLayout>

Hier ist die verfeinerte Version der Klasse, die zu funktionieren scheint und keine Probleme hat, die andere Lösungen haben:

package org.solovyev.android.views.llm;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;

/**
 * {@link android.support.v7.widget.LinearLayoutManager} which wraps its content. Note that this class will always
 * wrap the content regardless of {@link android.support.v7.widget.RecyclerView} layout parameters.
 *
 * Now it's impossible to run add/remove animations with child views which have arbitrary dimensions (height for
 * VERTICAL orientation and width for HORIZONTAL). However if child views have fixed dimensions
 * {@link #setChildSize(int)} method might be used to let the layout manager know how big they are going to be.
 * If animations are not used at all then a normal measuring procedure will run and child views will be measured during
 * the measure pass.
 */
public class LinearLayoutManager extends android.support.v7.widget.LinearLayoutManager {

    private static final int CHILD_WIDTH = 0;
    private static final int CHILD_HEIGHT = 1;
    private static final int DEFAULT_CHILD_SIZE = 100;

    private final int[] childDimensions = new int[2];

    private int childSize = DEFAULT_CHILD_SIZE;
    private boolean hasChildSize;

    @SuppressWarnings("UnusedDeclaration")
    public LinearLayoutManager(Context context) {
        super(context);
    }

    @SuppressWarnings("UnusedDeclaration")
    public LinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
        super(context, orientation, reverseLayout);
    }

    public static int makeUnspecifiedSpec() {
        return View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    }

    @Override
    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {
        final int widthMode = View.MeasureSpec.getMode(widthSpec);
        final int heightMode = View.MeasureSpec.getMode(heightSpec);

        final int widthSize = View.MeasureSpec.getSize(widthSpec);
        final int heightSize = View.MeasureSpec.getSize(heightSpec);

        final boolean exactWidth = widthMode == View.MeasureSpec.EXACTLY;
        final boolean exactHeight = heightMode == View.MeasureSpec.EXACTLY;

        final int unspecified = makeUnspecifiedSpec();

        if (exactWidth && exactHeight) {
            // in case of exact calculations for both dimensions let's use default "onMeasure" implementation
            super.onMeasure(recycler, state, widthSpec, heightSpec);
            return;
        }

        final boolean vertical = getOrientation() == VERTICAL;

        initChildDimensions(widthSize, heightSize, vertical);

        int width = 0;
        int height = 0;

        // it's possible to get scrap views in recycler which are bound to old (invalid) adapter entities. This
        // happens because their invalidation happens after "onMeasure" method. As a workaround let's clear the
        // recycler now (it should not cause any performance issues while scrolling as "onMeasure" is never
        // called whiles scrolling)
        recycler.clear();

        final int stateItemCount = state.getItemCount();
        final int adapterItemCount = getItemCount();
        // adapter always contains actual data while state might contain old data (f.e. data before the animation is
        // done). As we want to measure the view with actual data we must use data from the adapter and not from  the
        // state
        for (int i = 0; i < adapterItemCount; i++) {
            if (vertical) {
                if (!hasChildSize) {
                    if (i < stateItemCount) {
                        // we should not exceed state count, otherwise we'll get IndexOutOfBoundsException. For such items
                        // we will use previously calculated dimensions
                        measureChild(recycler, i, widthSpec, unspecified, childDimensions);
                    } else {
                        logMeasureWarning(i);
                    }
                }
                height += childDimensions[CHILD_HEIGHT];
                if (i == 0) {
                    width = childDimensions[CHILD_WIDTH];
                }
                if (height >= heightSize) {
                    break;
                }
            } else {
                if (!hasChildSize) {
                    if (i < stateItemCount) {
                        // we should not exceed state count, otherwise we'll get IndexOutOfBoundsException. For such items
                        // we will use previously calculated dimensions
                        measureChild(recycler, i, unspecified, heightSpec, childDimensions);
                    } else {
                        logMeasureWarning(i);
                    }
                }
                width += childDimensions[CHILD_WIDTH];
                if (i == 0) {
                    height = childDimensions[CHILD_HEIGHT];
                }
                if (width >= widthSize) {
                    break;
                }
            }
        }

        if ((vertical && height < heightSize) || (!vertical && width < widthSize)) {
            // we really should wrap the contents of the view, let's do it

            if (exactWidth) {
                width = widthSize;
            } else {
                width += getPaddingLeft() + getPaddingRight();
            }

            if (exactHeight) {
                height = heightSize;
            } else {
                height += getPaddingTop() + getPaddingBottom();
            }

            setMeasuredDimension(width, height);
        } else {
            // if calculated height/width exceeds requested height/width let's use default "onMeasure" implementation
            super.onMeasure(recycler, state, widthSpec, heightSpec);
        }
    }

    private void logMeasureWarning(int child) {
        if (BuildConfig.DEBUG) {
            Log.w("LinearLayoutManager", "Can't measure child #" + child + ", previously used dimensions will be reused." +
                    "To remove this message either use #setChildSize() method or don't run RecyclerView animations");
        }
    }

    private void initChildDimensions(int width, int height, boolean vertical) {
        if (childDimensions[CHILD_WIDTH] != 0 || childDimensions[CHILD_HEIGHT] != 0) {
            // already initialized, skipping
            return;
        }
        if (vertical) {
            childDimensions[CHILD_WIDTH] = width;
            childDimensions[CHILD_HEIGHT] = childSize;
        } else {
            childDimensions[CHILD_WIDTH] = childSize;
            childDimensions[CHILD_HEIGHT] = height;
        }
    }

    @Override
    public void setOrientation(int orientation) {
        // might be called before the constructor of this class is called
        //noinspection ConstantConditions
        if (childDimensions != null) {
            if (getOrientation() != orientation) {
                childDimensions[CHILD_WIDTH] = 0;
                childDimensions[CHILD_HEIGHT] = 0;
            }
        }
        super.setOrientation(orientation);
    }

    public void clearChildSize() {
        hasChildSize = false;
        setChildSize(DEFAULT_CHILD_SIZE);
    }

    public void setChildSize(int childSize) {
        hasChildSize = true;
        if (this.childSize != childSize) {
            this.childSize = childSize;
            requestLayout();
        }
    }

    private void measureChild(RecyclerView.Recycler recycler, int position, int widthSpec, int heightSpec, int[] dimensions) {
        final View child = recycler.getViewForPosition(position);

        final RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) child.getLayoutParams();

        final int hPadding = getPaddingLeft() + getPaddingRight();
        final int vPadding = getPaddingTop() + getPaddingBottom();

        final int hMargin = p.leftMargin + p.rightMargin;
        final int vMargin = p.topMargin + p.bottomMargin;

        final int hDecoration = getRightDecorationWidth(child) + getLeftDecorationWidth(child);
        final int vDecoration = getTopDecorationHeight(child) + getBottomDecorationHeight(child);

        final int childWidthSpec = getChildMeasureSpec(widthSpec, hPadding + hMargin + hDecoration, p.width, canScrollHorizontally());
        final int childHeightSpec = getChildMeasureSpec(heightSpec, vPadding + vMargin + vDecoration, p.height, canScrollVertically());

        child.measure(childWidthSpec, childHeightSpec);

        dimensions[CHILD_WIDTH] = getDecoratedMeasuredWidth(child) + p.leftMargin + p.rightMargin;
        dimensions[CHILD_HEIGHT] = getDecoratedMeasuredHeight(child) + p.bottomMargin + p.topMargin;

        recycler.recycleView(child);
    }
}

Dies ist auch als Bibliothek verfügbar . Link zur relevanten Klasse .

AKTUALISIEREN

Mit dem Update der Android Support Library 23.2 sollten alle WRAP_CONTENT ordnungsgemäß funktionieren.

Bitte aktualisieren Sie die Version einer Bibliothek in der Gradle-Datei.

compile 'com.android.support:recyclerview-v7:23.2.0'

Ursprüngliche Antwort

Wie bei einer anderen Frage beantwortet, müssen Sie die ursprüngliche onMeasure () -Methode verwenden, wenn die Höhe Ihrer Recycler-Ansicht größer als die Bildschirmhöhe ist. Dieser Layout-Manager kann ItemDecoration berechnen und mit mehr scrollen.

    public class MyLinearLayoutManager extends LinearLayoutManager {

public MyLinearLayoutManager(Context context, int orientation, boolean reverseLayout)    {
    super(context, orientation, reverseLayout);
}

private int[] mMeasuredDimension = new int[2];

@Override
public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state,
                      int widthSpec, int heightSpec) {
    final int widthMode = View.MeasureSpec.getMode(widthSpec);
    final int heightMode = View.MeasureSpec.getMode(heightSpec);
    final int widthSize = View.MeasureSpec.getSize(widthSpec);
    final int heightSize = View.MeasureSpec.getSize(heightSpec);
    int width = 0;
    int height = 0;
    for (int i = 0; i < getItemCount(); i++) {
        measureScrapChild(recycler, i,
                View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                mMeasuredDimension);

        if (getOrientation() == HORIZONTAL) {
            width = width + mMeasuredDimension[0];
            if (i == 0) {
                height = mMeasuredDimension[1];
            }
        } else {
            height = height + mMeasuredDimension[1];
            if (i == 0) {
                width = mMeasuredDimension[0];
            }
        }
    }

    // If child view is more than screen size, there is no need to make it wrap content. We can use original onMeasure() so we can scroll view.
    if (height < heightSize && width < widthSize) {

        switch (widthMode) {
            case View.MeasureSpec.EXACTLY:
                width = widthSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        switch (heightMode) {
            case View.MeasureSpec.EXACTLY:
                height = heightSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        setMeasuredDimension(width, height);
    } else {
        super.onMeasure(recycler, state, widthSpec, heightSpec);
    }
}

private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
                               int heightSpec, int[] measuredDimension) {

   View view = recycler.getViewForPosition(position);

   // For adding Item Decor Insets to view
   super.measureChildWithMargins(view, 0, 0);
    if (view != null) {
        RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
        int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
                    getPaddingLeft() + getPaddingRight() + getDecoratedLeft(view) + getDecoratedRight(view), p.width);
            int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                    getPaddingTop() + getPaddingBottom() + getPaddingBottom() + getDecoratedBottom(view) , p.height);
            view.measure(childWidthSpec, childHeightSpec);

            // Get decorated measurements
            measuredDimension[0] = getDecoratedMeasuredWidth(view) + p.leftMargin + p.rightMargin;
            measuredDimension[1] = getDecoratedMeasuredHeight(view) + p.bottomMargin + p.topMargin;
            recycler.recycleView(view);
        }
    }
}

ursprüngliche Antwort: https://stackoverflow.com/a/28510031/1577792

Hier ist die c # -Version für Mono Android

/* 
* Ported by Jagadeesh Govindaraj (@jaganjan)
 *Copyright 2015 serso aka se.solovyev
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * Contact details
 *
 * Email: se.solovyev @gmail.com
 * Site:  http://se.solovyev.org
 */


using Android.Content;
using Android.Graphics;
using Android.Support.V4.View;
using Android.Support.V7.Widget;
using Android.Util;
using Android.Views;
using Java.Lang;
using Java.Lang.Reflect;
using System;
using Math = Java.Lang.Math;

namespace Droid.Helper
{
    public class WrapLayoutManager : LinearLayoutManager
    {
        private const int DefaultChildSize = 100;
        private static readonly Rect TmpRect = new Rect();
        private int _childSize = DefaultChildSize;
        private static bool _canMakeInsetsDirty = true;
        private static readonly int[] ChildDimensions = new int[2];
        private const int ChildHeight = 1;
        private const int ChildWidth = 0;
        private static bool _hasChildSize;
        private static  Field InsetsDirtyField = null;
        private static int _overScrollMode = ViewCompat.OverScrollAlways;
        private static RecyclerView _view;

        public WrapLayoutManager(Context context, int orientation, bool reverseLayout)
            : base(context, orientation, reverseLayout)
        {
            _view = null;
        }

        public WrapLayoutManager(Context context) : base(context)
        {
            _view = null;
        }

        public WrapLayoutManager(RecyclerView view) : base(view.Context)
        {
            _view = view;
            _overScrollMode = ViewCompat.GetOverScrollMode(view);
        }

        public WrapLayoutManager(RecyclerView view, int orientation, bool reverseLayout)
            : base(view.Context, orientation, reverseLayout)
        {
            _view = view;
            _overScrollMode = ViewCompat.GetOverScrollMode(view);
        }

        public void SetOverScrollMode(int overScrollMode)
        {
            if (overScrollMode < ViewCompat.OverScrollAlways || overScrollMode > ViewCompat.OverScrollNever)
                throw new ArgumentException("Unknown overscroll mode: " + overScrollMode);
            if (_view == null) throw new ArgumentNullException(nameof(_view));
            _overScrollMode = overScrollMode;
            ViewCompat.SetOverScrollMode(_view, overScrollMode);
        }

        public static int MakeUnspecifiedSpec()
        {
            return View.MeasureSpec.MakeMeasureSpec(0, MeasureSpecMode.Unspecified);
        }

        public override void OnMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec,
            int heightSpec)
        {
            var widthMode = View.MeasureSpec.GetMode(widthSpec);
            var heightMode = View.MeasureSpec.GetMode(heightSpec);

            var widthSize = View.MeasureSpec.GetSize(widthSpec);
            var heightSize = View.MeasureSpec.GetSize(heightSpec);

            var hasWidthSize = widthMode != MeasureSpecMode.Unspecified;
            var hasHeightSize = heightMode != MeasureSpecMode.Unspecified;

            var exactWidth = widthMode == MeasureSpecMode.Exactly;
            var exactHeight = heightMode == MeasureSpecMode.Exactly;

            var unspecified = MakeUnspecifiedSpec();

            if (exactWidth && exactHeight)
            {
                // in case of exact calculations for both dimensions let's use default "onMeasure" implementation
                base.OnMeasure(recycler, state, widthSpec, heightSpec);
                return;
            }

            var vertical = Orientation == Vertical;

            InitChildDimensions(widthSize, heightSize, vertical);

            var width = 0;
            var height = 0;

            // it's possible to get scrap views in recycler which are bound to old (invalid) adapter
            // entities. This happens because their invalidation happens after "onMeasure" method.
            // As a workaround let's clear the recycler now (it should not cause any performance
            // issues while scrolling as "onMeasure" is never called whiles scrolling)
            recycler.Clear();

            var stateItemCount = state.ItemCount;
            var adapterItemCount = ItemCount;
            // adapter always contains actual data while state might contain old data (f.e. data
            // before the animation is done). As we want to measure the view with actual data we
            // must use data from the adapter and not from the state
            for (var i = 0; i < adapterItemCount; i++)
            {
                if (vertical)
                {
                    if (!_hasChildSize)
                    {
                        if (i < stateItemCount)
                        {
                            // we should not exceed state count, otherwise we'll get
                            // IndexOutOfBoundsException. For such items we will use previously
                            // calculated dimensions
                            MeasureChild(recycler, i, widthSize, unspecified, ChildDimensions);
                        }
                        else
                        {
                            LogMeasureWarning(i);
                        }
                    }
                    height += ChildDimensions[ChildHeight];
                    if (i == 0)
                    {
                        width = ChildDimensions[ChildWidth];
                    }
                    if (hasHeightSize && height >= heightSize)
                    {
                        break;
                    }
                }
                else
                {
                    if (!_hasChildSize)
                    {
                        if (i < stateItemCount)
                        {
                            // we should not exceed state count, otherwise we'll get
                            // IndexOutOfBoundsException. For such items we will use previously
                            // calculated dimensions
                            MeasureChild(recycler, i, unspecified, heightSize, ChildDimensions);
                        }
                        else
                        {
                            LogMeasureWarning(i);
                        }
                    }
                    width += ChildDimensions[ChildWidth];
                    if (i == 0)
                    {
                        height = ChildDimensions[ChildHeight];
                    }
                    if (hasWidthSize && width >= widthSize)
                    {
                        break;
                    }
                }
            }

            if (exactWidth)
            {
                width = widthSize;
            }
            else
            {
                width += PaddingLeft + PaddingRight;
                if (hasWidthSize)
                {
                    width = Math.Min(width, widthSize);
                }
            }

            if (exactHeight)
            {
                height = heightSize;
            }
            else
            {
                height += PaddingTop + PaddingBottom;
                if (hasHeightSize)
                {
                    height = Math.Min(height, heightSize);
                }
            }

            SetMeasuredDimension(width, height);

            if (_view == null || _overScrollMode != ViewCompat.OverScrollIfContentScrolls) return;
            var fit = (vertical && (!hasHeightSize || height < heightSize))
                      || (!vertical && (!hasWidthSize || width < widthSize));

            ViewCompat.SetOverScrollMode(_view, fit ? ViewCompat.OverScrollNever : ViewCompat.OverScrollAlways);
        }

        private void LogMeasureWarning(int child)
        {
#if DEBUG
            Log.WriteLine(LogPriority.Warn, "LinearLayoutManager",
                "Can't measure child #" + child + ", previously used dimensions will be reused." +
                "To remove this message either use #SetChildSize() method or don't run RecyclerView animations");
#endif
        }

        private void InitChildDimensions(int width, int height, bool vertical)
        {
            if (ChildDimensions[ChildWidth] != 0 || ChildDimensions[ChildHeight] != 0)
            {
                // already initialized, skipping
                return;
            }
            if (vertical)
            {
                ChildDimensions[ChildWidth] = width;
                ChildDimensions[ChildHeight] = _childSize;
            }
            else
            {
                ChildDimensions[ChildWidth] = _childSize;
                ChildDimensions[ChildHeight] = height;
            }
        }

        public void ClearChildSize()
        {
            _hasChildSize = false;
            SetChildSize(DefaultChildSize);
        }

        public void SetChildSize(int size)
        {
            _hasChildSize = true;
            if (_childSize == size) return;
            _childSize = size;
            RequestLayout();
        }

        private void MeasureChild(RecyclerView.Recycler recycler, int position, int widthSize, int heightSize,
            int[] dimensions)
        {
            View child = null;
            try
            {
                child = recycler.GetViewForPosition(position);
            }
            catch (IndexOutOfRangeException e)
            {
                Log.WriteLine(LogPriority.Warn, "LinearLayoutManager",
                    "LinearLayoutManager doesn't work well with animations. Consider switching them off", e);
            }

            if (child != null)
            {
                var p = child.LayoutParameters.JavaCast<RecyclerView.LayoutParams>()

                var hPadding = PaddingLeft + PaddingRight;
                var vPadding = PaddingTop + PaddingBottom;

                var hMargin = p.LeftMargin + p.RightMargin;
                var vMargin = p.TopMargin + p.BottomMargin;

                // we must make insets dirty in order calculateItemDecorationsForChild to work
                MakeInsetsDirty(p);
                // this method should be called before any getXxxDecorationXxx() methods
                CalculateItemDecorationsForChild(child, TmpRect);

                var hDecoration = GetRightDecorationWidth(child) + GetLeftDecorationWidth(child);
                var vDecoration = GetTopDecorationHeight(child) + GetBottomDecorationHeight(child);

                var childWidthSpec = GetChildMeasureSpec(widthSize, hPadding + hMargin + hDecoration, p.Width,
                    CanScrollHorizontally());
                var childHeightSpec = GetChildMeasureSpec(heightSize, vPadding + vMargin + vDecoration, p.Height,
                    CanScrollVertically());

                child.Measure(childWidthSpec, childHeightSpec);

                dimensions[ChildWidth] = GetDecoratedMeasuredWidth(child) + p.LeftMargin + p.RightMargin;
                dimensions[ChildHeight] = GetDecoratedMeasuredHeight(child) + p.BottomMargin + p.TopMargin;

                // as view is recycled let's not keep old measured values
                MakeInsetsDirty(p);
            }
            recycler.RecycleView(child);
        }

        private static void MakeInsetsDirty(RecyclerView.LayoutParams p)
        {
            if (!_canMakeInsetsDirty)
            {
                return;
            }
            try
            {
                if (InsetsDirtyField == null)
                {
                   var klass = Java.Lang.Class.FromType (typeof (RecyclerView.LayoutParams));
                    InsetsDirtyField = klass.GetDeclaredField("mInsetsDirty");
                    InsetsDirtyField.Accessible = true;
                }
                InsetsDirtyField.Set(p, true);
            }
            catch (NoSuchFieldException e)
            {
                OnMakeInsertDirtyFailed();
            }
            catch (IllegalAccessException e)
            {
                OnMakeInsertDirtyFailed();
            }
        }

        private static void OnMakeInsertDirtyFailed()
        {
            _canMakeInsetsDirty = false;
#if DEBUG
            Log.Warn("LinearLayoutManager",
                "Can't make LayoutParams insets dirty, decorations measurements might be incorrect");
#endif
        }
    }
}

RecyclerViewUnterstützung für wrap_contentin 23.2.0denen war fehlerhaft, 23.2.1 war nur stabil, so dass Sie verwenden können:

compile 'com.android.support:recyclerview-v7:24.2.0'

Sie können den Revisionsverlauf hier sehen:

https://developer.android.com/topic/libraries/support-library/revisions.html

Hinweis:

Beachten Sie auch , dass Support - Bibliothek nach der Aktualisierung der RecyclerViewrespektieren wrap_contentsowie match_parentso , wenn Sie einen Artikel Ansicht eines haben RecyclerViewSatz wie match_parentder Einzelansicht wird gesamten Bildschirm füllen

Dieser Kommentar hat mir geholfen.Put the recyclerview in any other layout (Relative layout is preferable). Then change recyclerview's height/width as match parent to that layout and set the parent layout's height/width as wrap content.

Das Problem beim Scrollen und Umbrechen von Text besteht darin, dass dieser Code davon ausgeht, dass sowohl die Breite als auch die Höhe auf eingestellt sind wrap_content. Es LayoutManagermuss jedoch bekannt sein, dass die horizontale Breite eingeschränkt ist. widthSpecVerwenden Sie also nicht das Original für jede untergeordnete Ansicht, sondern verwenden Sie einfach das Original widthSpec:

@Override
public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {
    final int widthMode = View.MeasureSpec.getMode(widthSpec);
    final int heightMode = View.MeasureSpec.getMode(heightSpec);
    final int widthSize = View.MeasureSpec.getSize(widthSpec);
    final int heightSize = View.MeasureSpec.getSize(heightSpec);
    int width = 0;
    int height = 0;
    for (int i = 0; i < getItemCount(); i++) {
        measureScrapChild(recycler, i,
                widthSpec,
                View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                mMeasuredDimension);

        if (getOrientation() == HORIZONTAL) {
            width = width + mMeasuredDimension[0];
            if (i == 0) {
                height = mMeasuredDimension[1];
            }
        } else {
            height = height + mMeasuredDimension[1];
            if (i == 0) {
                width = mMeasuredDimension[0];
            }
        }
    }
    switch (widthMode) {
        case View.MeasureSpec.EXACTLY:
            width = widthSize;
        case View.MeasureSpec.AT_MOST:
        case View.MeasureSpec.UNSPECIFIED:
    }

    switch (heightMode) {
        case View.MeasureSpec.EXACTLY:
            height = heightSize;
        case View.MeasureSpec.AT_MOST:
        case View.MeasureSpec.UNSPECIFIED:
    }

    setMeasuredDimension(width, height);
}

private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,int heightSpec, int[] measuredDimension) {
    View view = recycler.getViewForPosition(position);
    if (view != null) {
        RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
        int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                    getPaddingTop() + getPaddingBottom(), p.height);
        view.measure(widthSpec, childHeightSpec);
        measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;
        measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin;
        recycler.recycleView(view);
    }
}

Versuchen Sie dies (es ist eine böse Lösung, aber es kann funktionieren): In der onCreateMethode Ihres Activityoder in der onViewCreatedMethode Ihres Fragments. Stellen Sie einen Rückruf so ein, dass er beim RecyclerViewersten Rendern ausgelöst wird :

vRecyclerView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                calculeRecyclerViewFullHeight();
            }
        });

In der calculeRecyclerViewFullHeightBerechnung der RecyclerViewvollen Größe basierend auf der Größe seiner Kinder.

protected void calculateSwipeRefreshFullHeight() {
        int height = 0;
        for (int idx = 0; idx < getRecyclerView().getChildCount(); idx++ ) {
            View v = getRecyclerView().getChildAt(idx);
            height += v.getHeight();
        }
        SwipeRefreshLayout.LayoutParams params = getSwipeRefresh().getLayoutParams();
        params.height = height;
        getSwipeRefresh().setLayoutParams(params);
    }

In meinem Fall ist my RecyclerViewin a enthalten. Aus SwipeRefreshLayoutdiesem Grund setze ich die Höhe auf SwipeRefreshViewund nicht auf, RecyclerViewaber wenn Sie keine haben, können SwipeRefreshViewSie RecyclerViewstattdessen die Höhe auf einstellen .

Lassen Sie mich wissen, ob dies Ihnen geholfen hat oder nicht.

Dies funktioniert jetzt, da sie eine Version in Version 23.2 veröffentlicht haben, wie in diesem Beitrag angegeben . Zitiert den offiziellen Blogpost

Diese Version bringt eine aufregende neue Funktion in die LayoutManager-API: automatische Messung! Auf diese Weise kann sich ein RecyclerView basierend auf der Größe seines Inhalts selbst anpassen. Dies bedeutet, dass bisher nicht verfügbare Szenarien wie die Verwendung von WRAP_CONTENT für eine Dimension der RecyclerView jetzt möglich sind. Sie werden feststellen, dass alle integrierten LayoutManager jetzt die automatische Messung unterstützen.

Fügen Sie einfach Ihre RecyclerView in eine NestedScrollView ein. Funktioniert perfekt

<android.support.v4.widget.NestedScrollView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="10dp"
                android:layout_marginBottom="25dp">
                <android.support.v7.widget.RecyclerView
                    android:id="@+id/kliste"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent" />
            </android.support.v4.widget.NestedScrollView>

Ich hatte einige der oben genannten Lösungen verwendet, aber es funktionierte widthaber height.

1. Wenn Ihre Angabe compileSdkVersiongrößer als 23 ist , können Sie RecyclerView direkt verwenden, das in den jeweiligen Unterstützungsbibliotheken der Recycler-Ansicht bereitgestellt wird, wie dies bei 23 der Fall ist 'com.android.support:recyclerview-v7:23.2.1'. Diese Unterstützungsbibliotheken unterstützen Attribute wrap_contentfür Breite und Höhe.

Sie müssen es zu Ihren Abhängigkeiten hinzufügen

compile 'com.android.support:recyclerview-v7:23.2.1'

2. Wenn Sie compileSdkVersionweniger als 23 Jahre alt sind, können Sie die unten genannte Lösung verwenden.

Ich habe diesen Google-Thread zu diesem Problem gefunden. In diesem Thread gibt es einen Beitrag, der zur Implementierung von LinearLayoutManager führt .

Ich habe es sowohl auf Höhe als auch auf Breite getestet und es hat in beiden Fällen gut funktioniert.

/*
 * Copyright 2015 serso aka se.solovyev
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * Contact details
 *
 * Email: [email protected]
 * Site:  http://se.solovyev.org
 */

package org.solovyev.android.views.llm;

import android.content.Context;
import android.graphics.Rect;
import android.support.v4.view.ViewCompat;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;

import java.lang.reflect.Field;

/**
 * {@link android.support.v7.widget.LinearLayoutManager} which wraps its content. Note that this class will always
 * wrap the content regardless of {@link android.support.v7.widget.RecyclerView} layout parameters.
 * <p/>
 * Now it's impossible to run add/remove animations with child views which have arbitrary dimensions (height for
 * VERTICAL orientation and width for HORIZONTAL). However if child views have fixed dimensions
 * {@link #setChildSize(int)} method might be used to let the layout manager know how big they are going to be.
 * If animations are not used at all then a normal measuring procedure will run and child views will be measured during
 * the measure pass.
 */
public class LinearLayoutManager extends android.support.v7.widget.LinearLayoutManager {

    private static boolean canMakeInsetsDirty = true;
    private static Field insetsDirtyField = null;

    private static final int CHILD_WIDTH = 0;
    private static final int CHILD_HEIGHT = 1;
    private static final int DEFAULT_CHILD_SIZE = 100;

    private final int[] childDimensions = new int[2];
    private final RecyclerView view;

    private int childSize = DEFAULT_CHILD_SIZE;
    private boolean hasChildSize;
    private int overScrollMode = ViewCompat.OVER_SCROLL_ALWAYS;
    private final Rect tmpRect = new Rect();

    @SuppressWarnings("UnusedDeclaration")
    public LinearLayoutManager(Context context) {
        super(context);
        this.view = null;
    }

    @SuppressWarnings("UnusedDeclaration")
    public LinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
        super(context, orientation, reverseLayout);
        this.view = null;
    }

    @SuppressWarnings("UnusedDeclaration")
    public LinearLayoutManager(RecyclerView view) {
        super(view.getContext());
        this.view = view;
        this.overScrollMode = ViewCompat.getOverScrollMode(view);
    }

    @SuppressWarnings("UnusedDeclaration")
    public LinearLayoutManager(RecyclerView view, int orientation, boolean reverseLayout) {
        super(view.getContext(), orientation, reverseLayout);
        this.view = view;
        this.overScrollMode = ViewCompat.getOverScrollMode(view);
    }

    public void setOverScrollMode(int overScrollMode) {
        if (overScrollMode < ViewCompat.OVER_SCROLL_ALWAYS || overScrollMode > ViewCompat.OVER_SCROLL_NEVER)
            throw new IllegalArgumentException("Unknown overscroll mode: " + overScrollMode);
        if (this.view == null) throw new IllegalStateException("view == null");
        this.overScrollMode = overScrollMode;
        ViewCompat.setOverScrollMode(view, overScrollMode);
    }

    public static int makeUnspecifiedSpec() {
        return View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    }

    @Override
    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {
        final int widthMode = View.MeasureSpec.getMode(widthSpec);
        final int heightMode = View.MeasureSpec.getMode(heightSpec);

        final int widthSize = View.MeasureSpec.getSize(widthSpec);
        final int heightSize = View.MeasureSpec.getSize(heightSpec);

        final boolean hasWidthSize = widthMode != View.MeasureSpec.UNSPECIFIED;
        final boolean hasHeightSize = heightMode != View.MeasureSpec.UNSPECIFIED;

        final boolean exactWidth = widthMode == View.MeasureSpec.EXACTLY;
        final boolean exactHeight = heightMode == View.MeasureSpec.EXACTLY;

        final int unspecified = makeUnspecifiedSpec();

        if (exactWidth && exactHeight) {
            // in case of exact calculations for both dimensions let's use default "onMeasure" implementation
            super.onMeasure(recycler, state, widthSpec, heightSpec);
            return;
        }

        final boolean vertical = getOrientation() == VERTICAL;

        initChildDimensions(widthSize, heightSize, vertical);

        int width = 0;
        int height = 0;

        // it's possible to get scrap views in recycler which are bound to old (invalid) adapter entities. This
        // happens because their invalidation happens after "onMeasure" method. As a workaround let's clear the
        // recycler now (it should not cause any performance issues while scrolling as "onMeasure" is never
        // called whiles scrolling)
        recycler.clear();

        final int stateItemCount = state.getItemCount();
        final int adapterItemCount = getItemCount();
        // adapter always contains actual data while state might contain old data (f.e. data before the animation is
        // done). As we want to measure the view with actual data we must use data from the adapter and not from  the
        // state
        for (int i = 0; i < adapterItemCount; i++) {
            if (vertical) {
                if (!hasChildSize) {
                    if (i < stateItemCount) {
                        // we should not exceed state count, otherwise we'll get IndexOutOfBoundsException. For such items
                        // we will use previously calculated dimensions
                        measureChild(recycler, i, widthSize, unspecified, childDimensions);
                    } else {
                        logMeasureWarning(i);
                    }
                }
                height += childDimensions[CHILD_HEIGHT];
                if (i == 0) {
                    width = childDimensions[CHILD_WIDTH];
                }
                if (hasHeightSize && height >= heightSize) {
                    break;
                }
            } else {
                if (!hasChildSize) {
                    if (i < stateItemCount) {
                        // we should not exceed state count, otherwise we'll get IndexOutOfBoundsException. For such items
                        // we will use previously calculated dimensions
                        measureChild(recycler, i, unspecified, heightSize, childDimensions);
                    } else {
                        logMeasureWarning(i);
                    }
                }
                width += childDimensions[CHILD_WIDTH];
                if (i == 0) {
                    height = childDimensions[CHILD_HEIGHT];
                }
                if (hasWidthSize && width >= widthSize) {
                    break;
                }
            }
        }

        if (exactWidth) {
            width = widthSize;
        } else {
            width += getPaddingLeft() + getPaddingRight();
            if (hasWidthSize) {
                width = Math.min(width, widthSize);
            }
        }

        if (exactHeight) {
            height = heightSize;
        } else {
            height += getPaddingTop() + getPaddingBottom();
            if (hasHeightSize) {
                height = Math.min(height, heightSize);
            }
        }

        setMeasuredDimension(width, height);

        if (view != null && overScrollMode == ViewCompat.OVER_SCROLL_IF_CONTENT_SCROLLS) {
            final boolean fit = (vertical && (!hasHeightSize || height < heightSize))
                    || (!vertical && (!hasWidthSize || width < widthSize));

            ViewCompat.setOverScrollMode(view, fit ? ViewCompat.OVER_SCROLL_NEVER : ViewCompat.OVER_SCROLL_ALWAYS);
        }
    }

    private void logMeasureWarning(int child) {
        if (BuildConfig.DEBUG) {
            Log.w("LinearLayoutManager", "Can't measure child #" + child + ", previously used dimensions will be reused." +
                    "To remove this message either use #setChildSize() method or don't run RecyclerView animations");
        }
    }

    private void initChildDimensions(int width, int height, boolean vertical) {
        if (childDimensions[CHILD_WIDTH] != 0 || childDimensions[CHILD_HEIGHT] != 0) {
            // already initialized, skipping
            return;
        }
        if (vertical) {
            childDimensions[CHILD_WIDTH] = width;
            childDimensions[CHILD_HEIGHT] = childSize;
        } else {
            childDimensions[CHILD_WIDTH] = childSize;
            childDimensions[CHILD_HEIGHT] = height;
        }
    }

    @Override
    public void setOrientation(int orientation) {
        // might be called before the constructor of this class is called
        //noinspection ConstantConditions
        if (childDimensions != null) {
            if (getOrientation() != orientation) {
                childDimensions[CHILD_WIDTH] = 0;
                childDimensions[CHILD_HEIGHT] = 0;
            }
        }
        super.setOrientation(orientation);
    }

    public void clearChildSize() {
        hasChildSize = false;
        setChildSize(DEFAULT_CHILD_SIZE);
    }

    public void setChildSize(int childSize) {
        hasChildSize = true;
        if (this.childSize != childSize) {
            this.childSize = childSize;
            requestLayout();
        }
    }

    private void measureChild(RecyclerView.Recycler recycler, int position, int widthSize, int heightSize, int[] dimensions) {
        final View child;
        try {
            child = recycler.getViewForPosition(position);
        } catch (IndexOutOfBoundsException e) {
            if (BuildConfig.DEBUG) {
                Log.w("LinearLayoutManager", "LinearLayoutManager doesn't work well with animations. Consider switching them off", e);
            }
            return;
        }

        final RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) child.getLayoutParams();

        final int hPadding = getPaddingLeft() + getPaddingRight();
        final int vPadding = getPaddingTop() + getPaddingBottom();

        final int hMargin = p.leftMargin + p.rightMargin;
        final int vMargin = p.topMargin + p.bottomMargin;

        // we must make insets dirty in order calculateItemDecorationsForChild to work
        makeInsetsDirty(p);
        // this method should be called before any getXxxDecorationXxx() methods
        calculateItemDecorationsForChild(child, tmpRect);

        final int hDecoration = getRightDecorationWidth(child) + getLeftDecorationWidth(child);
        final int vDecoration = getTopDecorationHeight(child) + getBottomDecorationHeight(child);

        final int childWidthSpec = getChildMeasureSpec(widthSize, hPadding + hMargin + hDecoration, p.width, canScrollHorizontally());
        final int childHeightSpec = getChildMeasureSpec(heightSize, vPadding + vMargin + vDecoration, p.height, canScrollVertically());

        child.measure(childWidthSpec, childHeightSpec);

        dimensions[CHILD_WIDTH] = getDecoratedMeasuredWidth(child) + p.leftMargin + p.rightMargin;
        dimensions[CHILD_HEIGHT] = getDecoratedMeasuredHeight(child) + p.bottomMargin + p.topMargin;

        // as view is recycled let's not keep old measured values
        makeInsetsDirty(p);
        recycler.recycleView(child);
    }

    private static void makeInsetsDirty(RecyclerView.LayoutParams p) {
        if (!canMakeInsetsDirty) {
            return;
        }
        try {
            if (insetsDirtyField == null) {
                insetsDirtyField = RecyclerView.LayoutParams.class.getDeclaredField("mInsetsDirty");
                insetsDirtyField.setAccessible(true);
            }
            insetsDirtyField.set(p, true);
        } catch (NoSuchFieldException e) {
            onMakeInsertDirtyFailed();
        } catch (IllegalAccessException e) {
            onMakeInsertDirtyFailed();
        }
    }

    private static void onMakeInsertDirtyFailed() {
        canMakeInsetsDirty = false;
        if (BuildConfig.DEBUG) {
            Log.w("LinearLayoutManager", "Can't make LayoutParams insets dirty, decorations measurements might be incorrect");
        }
    }
}

Anstatt eine Bibliothek zu verwenden, ist es am einfachsten, b.android.com/74772 zu öffnen, bis die neue Version herauskommt . Dort finden Sie leicht die beste bisher bekannte Lösung.

PS: b.android.com/74772#c50 hat bei mir funktioniert

Ich empfehle Ihnen, die Recycling-Ansicht in ein anderes Layout einzufügen (ein relatives Layout ist vorzuziehen). Ändern Sie dann die Höhe / Breite von recyclerview als übergeordnetes Element zu diesem Layout und legen Sie die Höhe / Breite des übergeordneten Layouts als Wrap-Inhalt fest. Für mich geht das

Ersetzen Sie, measureScrapChildum dem folgenden Code zu folgen:

private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
        int heightSpec, int[] measuredDimension)
    {
        View view = recycler.GetViewForPosition(position);
        if (view != null)
        {
            MeasureChildWithMargins(view, widthSpec, heightSpec);
            measuredDimension[0] = view.MeasuredWidth;
            measuredDimension[1] = view.MeasuredHeight;
            recycler.RecycleView(view);
        }
    }