ListView每当我实施分组时,我都会遇到主要的性能问题。我在 StackOverflow 上发现了一些类似的问题,但似乎没有任何帮助!
这是我目前的情况(我已经简化了我的项目,所以噪音更少):
我有一个ContentControl和一个ListView一样的孩子。ListView绑定到一个ObservableCollection,它最初是空的。随着时间的推移,对象被添加到集合中(在此示例中,每 10 秒使用 500 个项目添加DispatcherTimer)。会的大小ObservableCollection会有所不同,但该系列最终可能会超过 25,000 件。
当ObservableCollection小于 2000(不是确切的数字)时,列大小调整如下所示:

但是,随着更多对象添加到 中ObservableCollection,性能会显着下降(您需要向下滚动才能发生这种情况)。  

这最终将导致Application锁定。
我认为可以使用解决问题Virtualization,所以我尝试使用以下方法:
<ListView x:Name="ListView1"
                  Style="{DynamicResource lvStyle}"
                  VirtualizingPanel.IsVirtualizingWhenGrouping="True"
                  VirtualizingPanel.IsVirtualizing="True"
                  VirtualizingPanel.IsContainerVirtualizable="True"
                  ScrollViewer.IsDeferredScrollingEnabled="True">
但是,似乎没有任何效果!
更不用说,VirtualizingPanel.IsVirtualizingWhenGrouping="True"导致ListView完全锁定。
我还研究了Paul McClean 出色的数据虚拟化,但是它不处理分组。
问题:  在对 a 中的项目进行分组时ListView,有没有办法调整列的大小而不会显着影响应用程序的性能?
理想情况下,我想减少内存开销,所以我完全支持实现某种异步解决方案。
代码:
XAML:
<ContentControl x:Class="ListViewDemo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
        xmlns:local="clr-namespace:ListViewDemo"
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        xmlns:dat="clr-namespace:System.Windows.Data;assembly=PresentationFramework"
        xmlns:Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Classic" 
        mc:Ignorable="d" 
        d:DesignHeight="400" d:DesignWidth="300">
    <ContentControl.Resources>
    <Style x:Key="lvStyle" TargetType="{x:Type ListView}">
        <Setter Property="VirtualizingStackPanel.IsVirtualizing" Value="True"/>
        <Setter Property="VirtualizingStackPanel.VirtualizationMode" Value="Recycling"/>
        <Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="True"/>
        <Setter Property="ListView.ItemsSource" Value="{Binding}"/>
        <Setter Property="ListView.View">
            <Setter.Value>
                <GridView>
                    <GridViewColumn Header="Name">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <TextBlock Text="{Binding Name}"/>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                    <GridViewColumn Header="Date">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <TextBlock Text="{Binding Date}"/>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                    <GridViewColumn Header="Desc">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <TextBlock Text="{Binding Desc}"/>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                </GridView>
            </Setter.Value>
        </Setter>
        </Style>
    </ContentControl.Resources>
    <Grid>
        <ListView x:Name="ListView1"
                      Style="{DynamicResource lvStyle}"
                      VirtualizingPanel.IsVirtualizingWhenGrouping="True"
                      VirtualizingPanel.IsVirtualizing="True"
                      VirtualizingPanel.IsContainerVirtualizable="True"
                      ScrollViewer.IsDeferredScrollingEnabled="True">
            <ListView.GroupStyle>
                <GroupStyle>
                    <GroupStyle.ContainerStyle>
                        <Style TargetType="{x:Type GroupItem}">
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate TargetType="{x:Type GroupItem}">
                                        <DockPanel>
                                            <Border DockPanel.Dock="Top">
                                                <TextBlock x:Name="groupItem"
                                                            Text="{Binding ItemCount, StringFormat={}({0} Results)}"></TextBlock>
                                            </Border>
                                            <ItemsPresenter DockPanel.Dock="Bottom"></ItemsPresenter>
                                        </DockPanel>
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </GroupStyle.ContainerStyle>
                </GroupStyle>
            </ListView.GroupStyle>
        </ListView>
    </Grid>
</ContentControl>
代码隐藏:
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Windows.Threading;
namespace ListViewDemo
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : ContentControl
    {
        private ObservableCollection<Event> eventCollection = new ObservableCollection<Event>();
        public MainWindow()
        {
            InitializeComponent();
            DispatcherTimer dispatcherTimer = new DispatcherTimer();
            dispatcherTimer.Tick += new EventHandler(dispatcherTimer_Tick);
            dispatcherTimer.Interval = new TimeSpan(0, 0, 10);
            dispatcherTimer.Start();
            ListView1.ItemsSource = eventCollection;
            ListView1.Items.SortDescriptions.Add(new SortDescription("Name", ListSortDirection.Descending));
            ListView1.Items.SortDescriptions.Add(new SortDescription("Date", ListSortDirection.Descending));
            ListView1.Items.GroupDescriptions.Add(new PropertyGroupDescription("Seconds"));
        }
        private void dispatcherTimer_Tick(object sender, EventArgs e)
        {
            for(var i = 0; i < 500; i++){
                eventCollection.Add(new Event
                {
                    Name = string.Format("Name_{0}", eventCollection.Count),
                    Date = DateTime.Now.ToString("MM.dd.yy HH:mm"),
                    Seconds = Convert.ToInt32(DateTime.Now.ToString("ss")),
                    Desc = "Description"
                });
            }
        }
        public class Event
        {
            public string Name { get; set; }
            public string Date { get; set; }
            public int Seconds { get; set; }
            public string Desc { get; set; }
        }
    }
}