WPF ItemsControl ItemsSource中的当前ListItem索引 [英] WPF ItemsControl the current ListItem Index in the ItemsSource

问题描述

是否可以在ItemsControl中知道当前项目的索引？

Is it possible to know the current item's Index in a ItemsControl?

编辑这有效！

<Window.Resources>

    <x:Array Type="{x:Type sys:String}" x:Key="MyArray">
        <sys:String>One</sys:String>
        <sys:String>Two</sys:String>
        <sys:String>Three</sys:String>
    </x:Array>

</Window.Resources>

<ItemsControl ItemsSource="{StaticResource MyArray}" AlternationCount="100">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <StackPanel Margin="10">

               <!-- one -->
               <TextBlock Text="{Binding Path=., 
                    StringFormat={}Value is {0}}" />

               <!-- two -->
                <TextBlock Text="{Binding Path=(ItemsControl.AlternationIndex), 
                    RelativeSource={RelativeSource TemplatedParent}, 
                    FallbackValue=FAIL, 
                    StringFormat={}Index is {0}}" />

               <!-- three -->
                <TextBlock Text="{Binding Path=Items.Count, 
                    RelativeSource={RelativeSource FindAncestor, 
                        AncestorType={x:Type ItemsControl}}, 
                    StringFormat={}Total is {0}}" />

            </StackPanel>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

看起来像这样：

< img src =https://i.stack.imgur.com/Dnysv.pngalt =在此处输入图像说明>

推荐答案

我刚才问了同样的事情这里

I asked the same thing a while ago here

没有内置索引属性，但您可以将ItemsControl的 AlternationCount 设置为高于项目数的值，并绑定到 AlternationIndex

There isn't a built in Index property, but you can set the AlternationCount of your ItemsControl to something higher than your item count, and bind to the AlternationIndex

<TextBlock Text="{Binding 
    Path=(ItemsControl.AlternationIndex), 
    RelativeSource={RelativeSource Mode=TemplatedParent}, 
    FallbackValue=FAIL, 
    StringFormat={}Index is {0}}" />

应该注意，如果ListBox使用虚拟化作为这里指出了一个网络指南。

It should be noted that this solution may not work if your ListBox uses Virtualization as bradgonesurfing pointed out here.

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