Question

我正在尝试在ListView中虚拟化我的用户控件，如下所示：

 <ListView VirtualizingStackPanel.IsVirtualizing="True"
                        VirtualizingStackPanel.CleanUpVirtualizedItem="stackPanel1_CleanUpVirtualizedItem"
                        VirtualizingStackPanel.VirtualizationMode="Standard"
                        Height="239" HorizontalAlignment="Left" Name="stackPanel1" VerticalAlignment="Top" Width="133" >              

                <ListView.Items>
                    <me:UserControl1 Backg="Green" />
                    <me:UserControl1 Backg="Blue" />
                    <me:UserControl1 Backg="Black" />
                    <me:UserControl1 Backg="Red" />
                    <me:UserControl1 Backg="Green" />
                    <me:UserControl1 Backg="Blue" />
                    <me:UserControl1 Backg="Black" />
                    <me:UserControl1 Backg="Red" />
                    <me:UserControl1 Backg="Blue" />
                    <me:UserControl1 Backg="Black" />
                     <me:UserControl1 Backg="Green" />
                    <me:UserControl1 Backg="Green" />
                </ListView.Items>
</ListView>

但是，虚拟化不起作用，如果我使用Rectangle作为项目，虚拟化只是工作，如下所示：

  <ListView VirtualizingStackPanel.IsVirtualizing="True"
                        VirtualizingStackPanel.CleanUpVirtualizedItem="stackPanel1_CleanUpVirtualizedItem"
                        VirtualizingStackPanel.VirtualizationMode="Standard"
                        Height="239" HorizontalAlignment="Left" Name="stackPanel1" VerticalAlignment="Top" Width="133" >              

                <ListView.Items>
                    <Rectangle Width="20" Height="20" Fill="Gray" ></Rectangle>
                <Rectangle Width="20" Height="20" Fill="Green"></Rectangle>
                <Rectangle Width="20" Height="20" Fill="Orange"></Rectangle>
                <Rectangle Width="20" Height="20" Fill="Blue"></Rectangle>
                <Rectangle Width="20" Height="20" Fill="Black"></Rectangle>
                <Rectangle Width="20" Height="20" Fill="Red"></Rectangle>
                <Rectangle Width="20" Height="20" Fill="Gray"></Rectangle>
                <Rectangle Width="20" Height="20" Fill="Green"></Rectangle>
                <Rectangle Width="20" Height="20" Fill="Orange"></Rectangle>
                </ListView.Items>
</ListView>

UserControl1 XAML是这样的：

<UserControl x:Class="WpfApplication3.UserControl1"
             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" 
             Width="20" Height="20"
            >
    <Grid>
        <Rectangle Name="internalRect" Width="20" Height="20" Fill="Black"></Rectangle>
    </Grid>
</UserControl>

我使用事件CleanUpVirtualizedItem来检测虚拟化是否有效，在滚动视图列表时，事件将仅使用矩形触发，而不是UserControl1，任何想法？

Answer 1

你如何知道它是否适用于矩形？我真的很怀疑，矩形只是非常轻巧。如果您静态创建项目，则无法进行任何虚拟化，则始终会创建项目。您需要设置ItemsSource并让控件创建项目，因为您可以设置包含用户控件的ItemTemplate。

为什么ListView没有虚拟化我的用户控件？

1 个答案: