将WrapPanel虚拟化为ListView的ItemsTemplate

问题描述

我的窗口中有一个ListView. ListView的默认ItemsPanel被替换为WrapPanel.我也有一个DataTemplate，因为它是ListViewItem.在运行系统中，主窗口将在一段时间内没有响应，因为ListView具有超过700个(并不断增加)ListViewItem(来自数据绑定).有没有办法使主窗口保持响应状态?

I have a ListView in my window. The ListView's default ItemsPanel was replaced with WrapPanel. I also have a DataTemplate for it's ListViewItems. In Runtime, main window will not responding for some time because the ListView have more than 700 (and keep increasing) ListViewItems (from data binding). Is there a way to keep the main window responsive?

可选:当ListView未准备好时，我希望在ListView上显示一个文本(或ProgressBar，如果可能的话)，并说请稍候..."或正在加载项目". ..".

OPTIONAL: When the ListView is not ready, i want a text (or ProgressBar if possible) show up over the ListView and saying something like "Please Wait..." or maybe "Loading Items...".

XAML:

 <ListView x:Name="MyListView" VirtualizingPanel.IsVirtualizing="True" VirtualizingPanel.VirtualizationMode="Recycling" HorizontalAlignment="Left"  Height="577" VerticalAlignment="Top" Width="902" ScrollViewer.HorizontalScrollBarVisibility="Auto" Foreground="Black" Margin="10,10,0,0" ScrollViewer.CanContentScroll="True" BorderBrush="#FFC54B4B" BorderThickness="3" Background="White">
                    <ListView.ItemsPanel>
                        <ItemsPanelTemplate>
                            <WrapPanel MaxWidth="{Binding (FrameworkElement.ActualWidth), 
                                RelativeSource={RelativeSource AncestorType=ScrollContentPresenter}}"
                                ItemWidth="{Binding (ListView.View).ItemWidth, 
                                RelativeSource={RelativeSource AncestorType=ListView}}"
                                MinWidth="{Binding ItemWidth, RelativeSource={RelativeSource Self}}"
                                ItemHeight="{Binding (ListView.View).ItemHeight, 
                                RelativeSource={RelativeSource AncestorType=ListView}}" />
                        </ItemsPanelTemplate>
                    </ListView.ItemsPanel>
</ListView>

我尝试过:

List<something> MyList = new List<something>(); 

ThreadPool.QueueUserWorkItem(_ =>
      {

          ( Create MyList here...)

          Dispatcher.BeginInvoke(new Action(() =>
          {
              MyListView.ItemsSource = MyList;
          }));
      });

在ListView准备就绪之前，主窗口仍然没有响应.

Main window is still not responding until the ListView ready.

推荐答案

谷歌搜索一段时间后.在这篇文章中，对WrapPanel进行虚拟化并非没有可能！方法如下:

After googling for some time. Thx to this article, Virtualizing WrapPanel is not impossible! Here's how:

1. 从此处
下载代码
2. 将其添加到您的项目中(在VS2010中:项目">添加现有项")

3. 将名称空间添加到您的XAML:

1. Download the code from here
2. Add it to your project (In VS2010: Project > Add Existing Item)

3. Add the namespace to your XAML:

xmlns:mwc="clr-namespace:MyWinCollection"

将VirtualizingWrapPanel用作ListView的ItemsTemplate:

Use VirtualizingWrapPanel as your ListView's ItemsTemplate:

<ListView x:Name="MyListView" ItemsSource="{StaticResource ItemCollection}">
  <ListView.ItemsPanel>
     <ItemsPanelTemplate>

        <VirtualizingWrapPanel Orientation="Horizontal"/> 

     </ItemsPanelTemplate>
   </ListView.ItemsPanel> 
</ListView>

完成！

由于并非所有项目都能一次渲染，因此主窗口现在可以完全响应.

Since not all items are rendered at once, the main window is fully responsive now.

希望这项帮助！ :D

Hopes this help! :D

顺便说一句，伙计们！你们救了我的一天.

Btw, thx guys! You guys saved my day.

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