WPF数据网格选择+扩展器的问题

我有一个包含rowdetailstemplate数据网格的扩展器。

当我单击数据网格行以查看行详细信息模板时，展开器关闭!

谁知道为什么和如何解决这个问题?

<标题> 更新

结果是发生了别的事情:

扩展符都包含在TabItem中。当我点击网格行，TabControls。SelectionChanged触发(为什么!? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?!)然后数据被重新计算和反弹。

所以真正的问题是为什么点击一个DataGrid行导致父TabControl的SelectionChanged事件触发?这里是XAML:

<Window xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"  x:Class="BPPDemo.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:BPPDemo"
    Title="BPP Demo" Height="600" Width="700" Loaded="Window_Loaded">
<Window.Resources>
    <local:AddrStatusColorConverter x:Key="addressStatusColorConverter"/>
    <local:BoolToVisConverter x:Key="boolToVisConverter"/>
</Window.Resources>
<DockPanel>
    <Menu DockPanel.Dock="Top">
        <Menu.Items>
            <MenuItem Header="File">
                <MenuItem Header="Open Assessment" Command="{Binding SelectAssessmentCommand}"></MenuItem>
                <MenuItem Header="Import Properties" Command="{Binding ImportPropertiesCommand}"></MenuItem>
            </MenuItem>
            <MenuItem Header="Properties" Visibility="{Binding IsSelected, ElementName=tabProperties,Converter={StaticResource boolToVisConverter}}">
                <MenuItem Header="Delete All Properties" Command="{Binding DeleteAllPropertiesCommand}"></MenuItem>
                <MenuItem Header="Resolve Invalid Addresses" Command="{Binding ValidateAddressesCommand}"></MenuItem>
                <MenuItem Header="Select Situs" Command="{Binding SelectSitusCommand}"/>
            </MenuItem>
        </Menu.Items>
    </Menu>
    <DockPanel Margin="10">
        <TextBlock Text="{Binding Assessment.Name}" FontWeight="Normal" FontSize="24" Foreground="#FF5C9EB7" DockPanel.Dock="Top" Margin="0,0,0,10"/>
        <TabControl SelectionChanged="TabControl_SelectionChanged">
            <TabItem x:Name="tabProperties" Header="Properties">
                <DataGrid ItemsSource="{Binding Properties}" AutoGenerateColumns="False" IsReadOnly="True" SelectedItem="{Binding SelectedProperty,Mode=TwoWay}">
                    <DataGrid.Columns>
                        <DataGridTextColumn Header="Description" Binding="{Binding Description}"/>
                        <DataGridTextColumn Header="Cost" Binding="{Binding Cost,StringFormat='{}{0:c}'}"/>
                        <DataGridTextColumn Header="Year Acquired" Binding="{Binding YearAcquired}"/>
                        <DataGridTextColumn Header="Life In Years" Binding="{Binding LifeInYears}"/>
                        <DataGridTextColumn Header="Schedule" Binding="{Binding Schedule}"/>
                        <DataGridTextColumn Header="Current Value" Binding="{Binding CurrentValue,StringFormat='{}{0:c}'}" />
                        <DataGridTextColumn Header="Tax" Binding="{Binding Tax,StringFormat='{}{0:c}'}" />
                        <DataGridTemplateColumn Header="Address">
                            <DataGridTemplateColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBlock Text="{Binding Address}" Foreground="{Binding AddressStatus, Converter={StaticResource addressStatusColorConverter}}"/>
                                </DataTemplate>
                            </DataGridTemplateColumn.CellTemplate>
                        </DataGridTemplateColumn>
                        <DataGridTextColumn Header="Address Status" Binding="{Binding AddressStatus}"/>
                        <DataGridTextColumn Header="Situs" Binding="{Binding Situs}"/>
                    </DataGrid.Columns>
                    <DataGrid.RowDetailsTemplate>
                        <DataTemplate>
                            <TextBlock>THIS ONE WORKS! WHY DOESN'T THE OTHER ONE????</TextBlock>
                        </DataTemplate>
                    </DataGrid.RowDetailsTemplate>

                </DataGrid>
            </TabItem>
            <TabItem Header="Listings" Name="tabListings">
                <DataGrid x:Name="SitusGroups" AutoGenerateColumns="false" SelectionMode="Single" SelectionUnit="FullRow">
                    <DataGrid.Columns>
                        <DataGridTextColumn Header="Situs" Binding="{Binding Situs,StringFormat='{}{0:c}',TargetNullValue='none'}"></DataGridTextColumn>
                        <DataGridTextColumn Header="Cost" Binding="{Binding Cost,StringFormat='{}{0:c}'}"></DataGridTextColumn>
                        <DataGridTextColumn Header="Value" Binding="{Binding Value,StringFormat='{}{0:c}'}"></DataGridTextColumn>
                        <DataGridTextColumn Header="Tax" Binding="{Binding Tax,StringFormat='{}{0:c}'}"></DataGridTextColumn>
                    </DataGrid.Columns>
                    <DataGrid.RowDetailsTemplate>
                        <DataTemplate>
                            <TextBlock>I JUST WANT TO SEE THIS WHEN I CLICK ON A ROW!</TextBlock>
                        </DataTemplate>
                    </DataGrid.RowDetailsTemplate>
                </DataGrid>
               
            </TabItem>
        </TabControl>
    </DockPanel>
</DockPanel>