要使 WPF 布局更快，您需要启用虚拟化。在您的代码中：
- 删除包裹所有控件的
ScrollViewer。
-
用ListBox替换顶级ItemsControl：
<ListBox Name="items" HorizontalContentAlignment="Stretch"
ScrollViewer.HorizontalScrollBarVisibility="Disabled" ... >
-
将ListBox 的ItemsPanel 中的StackPanel 替换为VirtualizingStackPanel：
<VirtualizingStackPanel Orientation="Vertical" ScrollUnit="Pixel"
VirtualizationMode="Recycling"/>
这将为顶级项目启用虚拟化。在我的电脑上，这允许在 1 秒内显示 100,000 个项目。
注意：
虽然您认为瓶颈是 WPF 布局，但您可能错了，因为您没有分析您的应用程序。因此，虽然这回答了您的问题，但它实际上可能无法解决窗口工作缓慢的问题。 Profiler 不仅可以分析您的代码，还可以分析框架代码。他们分析呼叫、内存等，而不是您的来源。它们是提高绩效的绝佳工具，也是找出绩效问题根源的唯一真正方法。
-
为了所有神圣的爱，请阅读http://sscce.org！如果您不尝试使您的示例简短、独立且可编译，那么您将没有足够的声誉来解决您所有的代码问题。为了运行您的示例，我必须创建自己的视图模型，摆脱所有不相关的代码，简化绑定，更不用说您自己的各种转换器、控件和绑定，这些都没有描述。
李>
已更新以支持 .NET 4.0
public static class PixelBasedScrollingBehavior
{
public static bool GetIsEnabled (DependencyObject obj)
{
return (bool)obj.GetValue(IsEnabledProperty);
}
public static void SetIsEnabled (DependencyObject obj, bool value)
{
obj.SetValue(IsEnabledProperty, value);
}
public static readonly DependencyProperty IsEnabledProperty =
DependencyProperty.RegisterAttached("IsEnabled", typeof(bool), typeof(PixelBasedScrollingBehavior),
new UIPropertyMetadata(false, IsEnabledChanged));
private static void IsEnabledChanged (DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var isEnabled = (bool)e.NewValue;
if (d is VirtualizingPanel) {
if (TrySetScrollUnit(d, isEnabled))
return;
if (!TrySetIsPixelBased(d, isEnabled))
throw new InvalidOperationException("Failed to set IsPixelBased or ScrollUnit property.");
}
if (d is ItemsControl) {
TrySetScrollUnit(d, isEnabled);
}
}
private static bool TrySetScrollUnit (DependencyObject ctl, bool isEnabled)
{
// .NET 4.5: ctl.SetValue(VirtualizingPanel.ScrollUnitProperty, isEnabled ? ScrollUnit.Pixel : ScrollUnit.Item);
var propScrollUnit = typeof(VirtualizingPanel).GetField("ScrollUnitProperty", BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy);
if (propScrollUnit == null)
return false;
var dpScrollUnit = (DependencyProperty)propScrollUnit.GetValue(null);
var assemblyPresentationFramework = typeof(Window).Assembly;
var typeScrollUnit = assemblyPresentationFramework.GetType("System.Windows.Controls.ScrollUnit");
if (typeScrollUnit == null)
return false;
var valueScrollUnit = Enum.Parse(typeScrollUnit, isEnabled ? "Pixel" : "Item");
ctl.SetValue(dpScrollUnit, valueScrollUnit);
return true;
}
private static bool TrySetIsPixelBased (DependencyObject ctl, bool isEnabled)
{
// .NET 4.0: ctl.IsPixelBased = isEnabled;
var propIsPixelBased = ctl.GetType().GetProperty("IsPixelBased", BindingFlags.NonPublic | BindingFlags.Instance);
if (propIsPixelBased == null)
return false;
propIsPixelBased.SetValue(ctl, isEnabled, null);
return true;
}
}
local:PixelBasedScrollingBehavior.IsEnabled="True"必须同时设置在ListBox和VirtualizingStackPanel上，否则滚动会在项目模式下工作。代码在 .NET 4.0 中编译。如果安装了 .NET 4.5，它将使用新属性。
工作示例：
MainWindow.xaml
<Window x:Class="So17371439ItemsLayoutBounty.MainWindow" x:Name="root"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:So17371439ItemsLayoutBounty"
Title="MainWindow">
<Window.Resources>
<Style x:Key="OrderRadioButton" TargetType="{x:Type RadioButton}"></Style>
<Style x:Key="OrderCheckboxButton" TargetType="{x:Type ToggleButton}"></Style>
<Style x:Key="OrderProductButton" TargetType="{x:Type Button}"></Style>
</Window.Resources>
<ListBox Name="items" ItemsSource="{Binding PreferenceGroups, ElementName=root}" HorizontalContentAlignment="Stretch" ScrollViewer.HorizontalScrollBarVisibility="Disabled" local:PixelBasedScrollingBehavior.IsEnabled="True">
<ItemsControl.Resources>
<ItemsPanelTemplate x:Key="wrapPanel">
<WrapPanel/>
</ItemsPanelTemplate>
<DataTemplate x:Key="SoloSelection" DataType="local:PreferenceGroup">
<ItemsControl ItemsSource="{Binding Preferences}" ItemsPanel="{StaticResource wrapPanel}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<RadioButton Width="146" Height="58" Margin="0,0,4,4" GroupName="{Binding GroupId}" Style="{StaticResource OrderRadioButton}">
<TextBlock Margin="4,0,3,0" VerticalAlignment="Center" TextWrapping="Wrap" Text="{Binding Name}"/>
</RadioButton>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
<DataTemplate x:Key="MultiSelection" DataType="local:PreferenceGroup">
<ItemsControl ItemsSource="{Binding Preferences}" ItemsPanel="{StaticResource wrapPanel}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<ToggleButton Width="146" Height="58" Margin="0,0,4,4" Style="{StaticResource OrderCheckboxButton}">
<TextBlock Margin="4,0,3,0" VerticalAlignment="Center" TextWrapping="Wrap" Text="{Binding Name}"/>
</ToggleButton>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
<DataTemplate x:Key="MultiQuantitySelection" DataType="local:PreferenceGroup">
<ItemsControl ItemsSource="{Binding Preferences}" ItemsPanel="{StaticResource wrapPanel}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid Width="146" Height="58" Margin="0,0,4,4">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Button Name="quantity" Background="White" Width="45" Style="{StaticResource OrderProductButton}">
<TextBlock Text="{Binding Quantity}"/>
</Button>
<Button Margin="-1,0,0,0" Grid.Column="1" HorizontalAlignment="Stretch" HorizontalContentAlignment="Left" Style="{StaticResource OrderProductButton}">
<TextBlock TextWrapping="Wrap" HorizontalAlignment="Left" TextTrimming="CharacterEllipsis" Text="{Binding Name}"/>
</Button>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
</ItemsControl.Resources>
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock FontSize="25" FontWeight="Light" Margin="0,8,0,5" Text="{Binding Name}"/>
<ContentControl Content="{Binding}" Name="items"/>
</StackPanel>
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding SelectionMode}" Value="1">
<Setter TargetName="items" Property="ContentTemplate" Value="{StaticResource SoloSelection}"/>
</DataTrigger>
<DataTrigger Binding="{Binding SelectionMode}" Value="2">
<Setter TargetName="items" Property="ContentTemplate" Value="{StaticResource MultiSelection}"/>
</DataTrigger>
<DataTrigger Binding="{Binding SelectionMode}" Value="3">
<Setter TargetName="items" Property="ContentTemplate" Value="{StaticResource MultiQuantitySelection}"/>
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
</ItemsControl.ItemTemplate>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel x:Name="panel" Orientation="Vertical" VirtualizationMode="Recycling" local:PixelBasedScrollingBehavior.IsEnabled="True"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ListBox>
</Window>
MainWindow.xaml.cs
using System;
using System.Collections.ObjectModel;
using System.Reflection;
using System.Windows;
using System.Windows.Controls;
namespace So17371439ItemsLayoutBounty
{
public partial class MainWindow
{
public ObservableCollection<PreferenceGroup> PreferenceGroups { get; private set; }
public MainWindow ()
{
var rnd = new Random();
PreferenceGroups = new ObservableCollection<PreferenceGroup>();
for (int i = 0; i < 100000; i++) {
var group = new PreferenceGroup { Name = string.Format("Group {0}", i), SelectionMode = rnd.Next(1, 4) };
int nprefs = rnd.Next(5, 40);
for (int j = 0; j < nprefs; j++)
group.Preferences.Add(new Preference { Name = string.Format("Pref {0}", j), Quantity = rnd.Next(100) });
PreferenceGroups.Add(group);
}
InitializeComponent();
}
}
public class PreferenceGroup
{
public string Name { get; set; }
public int SelectionMode { get; set; }
public ObservableCollection<Preference> Preferences { get; private set; }
public PreferenceGroup ()
{
Preferences = new ObservableCollection<Preference>();
}
}
public class Preference
{
public string Name { get; set; }
public string GroupId { get; set; }
public int Quantity { get; set; }
}
public static class PixelBasedScrollingBehavior
{
public static bool GetIsEnabled (DependencyObject obj)
{
return (bool)obj.GetValue(IsEnabledProperty);
}
public static void SetIsEnabled (DependencyObject obj, bool value)
{
obj.SetValue(IsEnabledProperty, value);
}
public static readonly DependencyProperty IsEnabledProperty =
DependencyProperty.RegisterAttached("IsEnabled", typeof(bool), typeof(PixelBasedScrollingBehavior),
new UIPropertyMetadata(false, IsEnabledChanged));
private static void IsEnabledChanged (DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var isEnabled = (bool)e.NewValue;
if (d is VirtualizingPanel) {
if (TrySetScrollUnit(d, isEnabled))
return;
if (!TrySetIsPixelBased(d, isEnabled))
throw new InvalidOperationException("Failed to set IsPixelBased or ScrollUnit property.");
}
if (d is ItemsControl) {
TrySetScrollUnit(d, isEnabled);
}
}
private static bool TrySetScrollUnit (DependencyObject ctl, bool isEnabled)
{
// .NET 4.5: ctl.SetValue(VirtualizingPanel.ScrollUnitProperty, isEnabled ? ScrollUnit.Pixel : ScrollUnit.Item);
var propScrollUnit = typeof(VirtualizingPanel).GetField("ScrollUnitProperty", BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy);
if (propScrollUnit == null)
return false;
var dpScrollUnit = (DependencyProperty)propScrollUnit.GetValue(null);
var assemblyPresentationFramework = typeof(Window).Assembly;
var typeScrollUnit = assemblyPresentationFramework.GetType("System.Windows.Controls.ScrollUnit");
if (typeScrollUnit == null)
return false;
var valueScrollUnit = Enum.Parse(typeScrollUnit, isEnabled ? "Pixel" : "Item");
ctl.SetValue(dpScrollUnit, valueScrollUnit);
return true;
}
private static bool TrySetIsPixelBased (DependencyObject ctl, bool isEnabled)
{
// .NET 4.0: ctl.IsPixelBased = isEnabled;
var propIsPixelBased = ctl.GetType().GetProperty("IsPixelBased", BindingFlags.NonPublic | BindingFlags.Instance);
if (propIsPixelBased == null)
return false;
propIsPixelBased.SetValue(ctl, isEnabled, null);
return true;
}
}
}