C# 单击项目时不触发选择更改

我是wpf新手，我想在组合框中使用DataGrid而不是default ItemPresenter并搜索和查找示例，但当我在组合框的嵌套数据网格中选择一个项目时，注意到发生了什么

这是可能的测试代码

<Style x:Key="DataGridComboBoxStyle" TargetType="{x:Type ComboBox}">
    <Setter Property="Foreground" Value="DimGray" />
    <Setter Property="BorderBrush" Value="LightGray" />
    <Setter Property="Background" Value="White" />
    <Setter Property="SnapsToDevicePixels" Value="True"/>
    <Setter Property="OverridesDefaultStyle" Value="True"/>
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
    <Setter Property="ScrollViewer.CanContentScroll" Value="true"/>
    <Setter Property="FontSize" Value="12" />
    <Setter Property="FontFamily" Value="Tahoma, Verdana" />
    <Setter Property="Height" Value="25" />
    <Setter Property="HorizontalContentAlignment" Value="Left" />
    <Setter Property="MaxDropDownHeight" Value="250" />
    <Setter Property="StaysOpenOnEdit" Value="True" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="ComboBox">
                <Grid>
                    <ToggleButton BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" Grid.ColumnSpan="2" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}">
                        <ToggleButton.Style>
                            <Style TargetType="{x:Type ToggleButton}">
                                <Setter Property="OverridesDefaultStyle" Value="True"/>
                                <Setter Property="IsTabStop" Value="False"/>
                                <Setter Property="Focusable" Value="False"/>
                                <Setter Property="ClickMode" Value="Press"/>
                                <Setter Property="Background" Value="Transparent"/>
                                <Setter Property="Template">
                                    <Setter.Value>
                                        <ControlTemplate TargetType="{x:Type ToggleButton}">
                                            <Themes:ButtonChrome x:Name="Chrome" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderPressed="{TemplateBinding IsPressed}" SnapsToDevicePixels="True">
                                                <Grid HorizontalAlignment="Right" Width="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}">
                                                    <Path x:Name="Arrow" Data="M0,0L3.5,4 7,0z" Fill="Black" HorizontalAlignment="Center" Margin="3,1,0,0" VerticalAlignment="Center"/>
                                                </Grid>
                                            </Themes:ButtonChrome>
                                            <ControlTemplate.Triggers>
                                                <Trigger Property="IsChecked" Value="True">
                                                    <Setter Property="RenderPressed" TargetName="Chrome" Value="True"/>
                                                </Trigger>
                                                <Trigger Property="IsEnabled" Value="False">
                                                    <Setter Property="Fill" TargetName="Arrow" Value="#FFAFAFAF"/>
                                                </Trigger>
                                            </ControlTemplate.Triggers>
                                        </ControlTemplate>
                                    </Setter.Value>
                                </Setter>
                            </Style>
                        </ToggleButton.Style>
                    </ToggleButton>
                    <ContentPresenter Name="ContentSite"
                                      IsHitTestVisible="False"
                                      Content="{Binding ElementName=ItemsPresenter, Path=SelectedItem}"
                                      ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}"
                                      ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}"
                                      Margin="10,3,30,3"
                                      VerticalAlignment="Center"
                                      HorizontalAlignment="Center" />
                    <TextBox x:Name="PART_EditableTextBox"
                             Style="{x:Null}"
                             SelectionBrush="Transparent"
                             Template="{DynamicResource  ComboBoxTextBox}"
                             Text="{Binding ElementName=ItemsPresenter, Path=SelectedItem}"
                             Foreground="{TemplateBinding Foreground}"
                             FontFamily="{TemplateBinding FontFamily}"
                             FontSize="{TemplateBinding FontSize}"
                             FontWeight="{TemplateBinding FontWeight}"
                             HorizontalAlignment="Stretch"
                             HorizontalContentAlignment="Left"
                             VerticalAlignment="Stretch"
                             VerticalContentAlignment="Center"
                             Background="Transparent"
                             Margin="3,3,23,3"
                             Focusable="True"                               
                             Visibility="Hidden"
                             IsReadOnly="{TemplateBinding IsReadOnly}"/>
                    <Popup Name="Popup"
                           Placement="Bottom"
                           IsOpen="{TemplateBinding IsDropDownOpen}"
                           AllowsTransparency="True"
                           Focusable="False"
                           PopupAnimation="Slide">
                        <Grid Name="DropDown"
                              SnapsToDevicePixels="True"               
                              MinWidth="{TemplateBinding ActualWidth}"
                              MaxHeight="{TemplateBinding MaxDropDownHeight}">
                            <Border x:Name="DropDownBorder"
                                    Background="White"
                                    BorderThickness="1"
                                    BorderBrush="LightGray"/>
                            <ScrollViewer Margin="1,2" SnapsToDevicePixels="True" VerticalScrollBarVisibility="Disabled" HorizontalScrollBarVisibility="Disabled">
                                <StackPanel Orientation="Vertical" >
                                    <telerik:RadGridView 
                                        Name="ItemPresenter" ScrollViewer.CanContentScroll="True" 
                                        ScrollViewer.HorizontalScrollBarVisibility="Auto" 
                                        ScrollViewer.VerticalScrollBarVisibility="Auto" 
                                        ItemsSource="{TemplateBinding ItemsSource}" 
                                        BorderBrush="Transparent" 
                                        ShowGroupPanel="False"
                                        RowHeight="20"
                                        KeyboardNavigation.DirectionalNavigation="Contained"
                                        AutoGenerateColumns ="False"
                                        CanUserDeleteRows="False">
                                        <telerik:RadGridView.Columns>
                                            <telerik:GridViewDataColumn DataMemberBinding="{Binding FullName, Mode=OneWay}" Header="نام خانوادگی" IsReadOnly="True" Width="auto"/>
                                            <telerik:GridViewDataColumn DataMemberBinding="{Binding FatherName, Mode=OneWay}" Header="نام پدر" IsReadOnly="True" Width="auto"/>
                                            <telerik:GridViewDataColumn DataMemberBinding="{Binding Phone, Mode=OneWay}" Header="شماره تلفن" IsReadOnly="True" Width="auto"/>
                                            <telerik:GridViewDataColumn DataMemberBinding="{Binding Mobile, Mode=OneWay}" Header="موبایل" IsReadOnly="True" Width="auto"/>
                                        </telerik:RadGridView.Columns>
                                    </telerik:RadGridView>

                                    <Border BorderBrush="LightGray" BorderThickness="0, 1, 0, 0">
                                        <DockPanel LastChildFill="True" Background="White" Margin="5">
                                            <Button Style="{DynamicResource  DataGridPagingButtonStyle}" DockPanel.Dock="Left" >
                                                <Button.Content>
                                                    <UniformGrid Margin="1">
                                                        <Path Height="20" Width="20" Stroke="DarkGray" Stretch="Uniform" StrokeThickness="1" Data="M 4,1  L 1,4  L 4,7" />
                                                    </UniformGrid>
                                                </Button.Content>
                                            </Button>
                                            <Button Style="{DynamicResource  DataGridPagingButtonStyle}" DockPanel.Dock="Right">
                                                <Button.Content>
                                                    <UniformGrid Margin="1">
                                                        <Path Height="20" Width="20" Stroke="DarkGray" Stretch="Uniform" StrokeThickness="1" Data="M1,1 L4,4 1,7" />
                                                    </UniformGrid>
                                                </Button.Content>
                                            </Button>
                                            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" DockPanel.Dock="Left">
                                                <TextBlock FontFamily="Tahoma, Verdana" FontSize="11" Foreground="DimGray" VerticalAlignment="Center" Padding="0, 0, 5, 2" Text="Page" />
                                                <TextBox BorderBrush="LightGray" FontFamily="Tahoma, Verdana" FontSize="11" Foreground="DimGray" Height="20" Width="20" HorizontalContentAlignment="Center" Text="1" />
                                                <TextBlock FontFamily="Tahoma, Verdana" FontSize="11" Foreground="DimGray" VerticalAlignment="Center" Padding="5, 0, 5, 2" Text="to" />
                                                <TextBlock FontFamily="Tahoma, Verdana" FontSize="11" Foreground="DimGray" VerticalAlignment="Center" Padding="0, 0, 0, 2" Text="(bind pages)" />
                                            </StackPanel>
                                        </DockPanel>
                                    </Border>
                                </StackPanel>
                            </ScrollViewer>
                        </Grid>
                    </Popup>
                </Grid>

            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

必须将嵌套数据网格的SelectedItem绑定到视图模型/代码隐藏中的属性。该方法集将被调用。同时删除不相关的代码如何访问嵌套数据网格？？数据网格以样式定义，然后样式应用于文本框