FindAncestor不适用于中的UserControlListView.ItemTemplate文件

<Window x:Class="TestUserControlBinding.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:system="clr-namespace:System;assembly=mscorlib"
        xmlns:local="clr-namespace:TestUserControlBinding"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <ListView>
            <ListView.ItemTemplate>
                <DataTemplate>
                    <!--<Label Content="{Binding IsSelected, RelativeSource={RelativeSource FindAncestor, AncestorType=ListViewItem}}" />-->
                    <local:MyUserControl Content="{Binding IsSelected, RelativeSource={RelativeSource FindAncestor, AncestorType=ListViewItem}}" />
                </DataTemplate>
            </ListView.ItemTemplate>
            <ListView.Items>
                <system:String>First</system:String>
                <system:String>Second</system:String>
                <system:String>Third</system:String>
            </ListView.Items>
        </ListView>
    </Grid>
</Window>

注释的标签行正常工作(如果在ListView中选中,则显示True,否则显示False)。

系统.Windows.Data错误:40: 在上找不到“Content”属性 '对象'''字符串' (HashCode=-1920739956)'。 装订xpression:路径=内容; DataItem='String' (HashCode=-1920739956);目标元素 是“Content”(类型为“Object”)

MyUserControl只包含绑定到Content属性的标签:

<Grid>
    <Label Content="{Binding Content}" />
</Grid>

有人知道为什么UserControl的行为不同于Label控件吗?(或者至少能帮我看看我明显遗漏了什么?)