我有DialogFragment，其中包含RecyclerView（卡片列表）。
这个RecyclerView中有一个或多个CardViews可以有任何高度。
我想根据其中包含的DialogFragment为此CardViews提供正确的高度。
通常情况下这很简单，我会像wrap_content这样设置RecyclerView。
<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>
因为我使用RecyclerView这不起作用，请参阅：
https://issuetracker.google.com/issues/37001674
和
Nested Recycler view height doesn't wrap its content
在这两个页面上，人们建议延长LinearLayoutManager并覆盖onMeasure()
我首先使用了第一个链接中提供的 LayoutManager ：
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);
}
}
}
然而这不起作用，因为
heightSize = View.MeasureSpec.getSize(heightSpec);
返回一个非常大的值，似乎与match_parent相关。
通过评论height = heightSize;（在第二个切换案例中）我设法使高度工作，但前提是TextView内的CardView子项没有包装自己的文本（长句子）。
只要TextView包装它自己的文本，高度应该增加，但事实并非如此。它将该长句的高度计算为单行，而不是换行（2或更多）。
有关如何改进此LayoutManager的任何建议，以便RecyclerView与WRAP_CONTENT一起使用？
编辑：此布局管理器可能适用于大多数人，但在滚动和计算包装文本视图的高度时仍然存在问题
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);
}
}
}
答案 0 :(得分：178)
从Android Support Library 23.2.1更新，所有 WRAP_CONTENT 都可以正常使用。
请在gradle文件或中更新库的版本以进一步：
compile 'com.android.support:recyclerview-v7:23.2.1'
解决了一些问题，比如修复了与各种测量规范方法相关的错误
检查http://developer.android.com/tools/support-library/features.html#v7-recyclerview
答案 1 :(得分：53)
以下是该类的精炼版本，似乎有效，并且缺少其他解决方案的问题：
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);
}
}
这也可以library的形式提供。链接到relevant class。
答案 2 :(得分：29)
终于找到了解决这个问题的方法。
您需要做的就是将RecyclerView包裹在RelativeLayout中。也许还有其他观点可能也有效。
<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>
答案 3 :(得分：16)
<强>更新
通过Android支持库23.2更新，所有WRAP_CONTENT都可以正常工作。
请在gradle文件中更新库的版本。
compile 'com.android.support:recyclerview-v7:23.2.0'
原始答案
正如其他问题所解答的，当您的回收者视图高度大于屏幕高度时，您需要使用原始的onMeasure（）方法。此布局管理器可以计算ItemDecoration并可以滚动更多。
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);
}
}
}
答案 4 :(得分：10)
以下是 c＃版本的单机版
/*
* 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
}
}
}
答案 5 :(得分：6)
RecyclerView在wrap_content中添加了对23.2.0的支持，这是错误的，23.2.1只是稳定的，所以你可以使用：
compile 'com.android.support:recyclerview-v7:24.2.0'
您可以在此处查看修订历史记录：
https://developer.android.com/topic/libraries/support-library/revisions.html
注意：
另请注意，更新支持库后，RecyclerView会尊重wrap_content以及match_parent，因此如果您将RecyclerView的项目视图设置为{{1}单个视图将填满整个屏幕
答案 6 :(得分：4)
滚动和文本换行的问题在于此代码假设宽度和高度都设置为wrap_content。但是，LayoutManager需要知道水平宽度受到约束。因此，不要为每个子视图创建自己的widthSpec，只需使用原始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);
}
}
答案 7 :(得分：3)
尝试这个（这是一个令人讨厌的解决方案，但它可能有效）：
在onCreate的{{1}}方法或片段的Activity方法中。设置一个回调准备好在onViewCreated首次渲染时触发，如下所示：
RecyclerView在vRecyclerView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
calculeRecyclerViewFullHeight();
}
});
根据孩子的身高计算calculeRecyclerViewFullHeight全高。
RecyclerView在我的情况下，我的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);
}
包含在RecyclerView中，因此我将高度设置为SwipeRefreshLayout而不是SwipeRefreshView，但如果你不知道没有任何RecyclerView，那么您可以将高度设置为SwipeRefreshView。
请告诉我这是否对您有所帮助。
答案 8 :(得分：3)
现在可以正常工作，因为他们已经在版本23.2中发布了一个版本，如post中所述。 引用官方blogpost
此版本为LayoutManager API带来了令人兴奋的新功能：自动测量！这允许RecyclerView根据其内容的大小调整自身大小。这意味着现在可以使用以前不可用的方案，例如使用WRAP_CONTENT作为RecyclerView的维度。您会发现所有内置的LayoutManagers现在都支持自动测量。
答案 9 :(得分：3)
只需将RecyclerView放在NestedScrollView中。完美运行
<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>
答案 10 :(得分：2)
我使用了上述某些解决方案，但它适用于width但height。
compileSdkVersion大于 23 ，您可以直接使用其各自的回收站视图支持库中提供的 RecyclerView ，例如 23 它将是'com.android.support:recyclerview-v7:23.2.1'。这些支持库支持wrap_content的宽度和高度属性。您必须将其添加到依赖项
compile 'com.android.support:recyclerview-v7:23.2.1'
compileSdkVersion小于 23 ，则可以使用下述解决方案。我在这个问题上找到了Google thread。在这个主题中，有一个贡献导致了LinearLayoutManager的实现。
我已经为 height 和 width 测试了它，在这两种情况下它都适用于我。
/*
* 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
*/
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");
}
}
}
答案 11 :(得分：2)
This comment helped me. 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.
答案 12 :(得分：1)
在新版本发布之前，最简单的解决方案是打开b.android.com/74772，而不是使用任何库。您可以轻松找到迄今为止已知的最佳解决方案。
PS：b.android.com/74772#c50为我工作
答案 13 :(得分：0)
尝试删除： mRecylerView.setHasFixedSize（true）;
答案 14 :(得分：0)
希望这对新手有帮助，我提到了我的公共github gist链接，您可以在其中看到我的代码段
https://gist.github.com/Abhishekgarg727/72d29bb4996809b2e097037c88392493
<script src="https://gist.github.com/Abhishekgarg727/72d29bb4996809b2e097037c88392493.js"></script>
答案 15 :(得分：0)
任何不想使用RecyclerView进行此布局的人 Recycler as GridView layout
只需像这样使用GridLayoutManager：
RecyclerView.LayoutManager mRecyclerGrid=new GridLayoutManager(this,3,LinearLayoutManager.VERTICAL,false);
mRecyclerView.setLayoutManager(mRecyclerGrid);
您可以设置一行中应该显示多少个项目（替换3）。
答案 16 :(得分：0)
我有和你类似的问题，我可以通过使用 LayoutManager 作为 StaggeredGridLayoutManager 而不是通过计算屏幕宽度或 LinearLayoutManager 尝试使用 GridLayoutManager 来解决它
请在下面找到示例代码，无需您进行任何其他自定义
StaggeredGridLayoutManager horizontalManager = new StaggeredGridLayoutManager(spanCount, StaggeredGridLayoutManager.HORIZONTAL);
mRecyclerView.setLayoutManager(horizontalManager);
注意：spanCount 是每行的项目数，但如果当前 RecyclerView 项目达到屏幕宽度，它将为您自动换行内容。
希望能帮到你，祝你好运！！！
答案 17 :(得分：0)
我建议你将recyclerview放在任何其他布局中（相对布局更可取）。然后将recyclerview的高度/宽度更改为与该布局匹配的父级，并将父级布局的高度/宽度设置为换行内容。它对我有用
答案 18 :(得分：0)
您必须将FrameLayout作为主视图放入使用ScrollView和至少您的RecyclerView放入RelativeLayout，它适用于我。
这里的真正诀窍是RelativeLayout ......
很乐意提供帮助。
答案 19 :(得分：0)
在Adapter viewholder onCreateViewHolder方法中使用null值而不是父视图组更新视图。
@Override
public AdapterItemSku.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflator.inflate(R.layout.layout_item, null, false);
return new MyViewHolder(view);
}
答案 20 :(得分：0)
将measureScrapChild替换为代码：
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);
}
}
我使用的是xamarin，所以这是c＃代码。我认为这可以很容易地“翻译”为Java。
答案 21 :(得分：-1)
我没有处理过我的答案，但我知道它的方式StaggridLayoutManager没有。网格1可以解决您的问题，因为StaggridLayout会根据内容的大小自动调整其高度和宽度。如果它的工作原理不要忘记检查它是一个正确的答案。欢呼..