WPF,用代码动态添加TabItem到TabControl中（TabItem应用了样式，并且添加了一个UserControl的View），无法呈现预计的View

Question

1.出问题的写法：

        private void CaseSheetNew_Click(object sender, RoutedEventArgs e)
        {
            //Zeta_tabWork 为TabControl ;CaseSheetView 为UserControl的View
            TabItem ti = new TabItem();

            /*下面这两句在这个位置的话，最后 Zeta_tabWork.SelectedItem = ti 并不能达到选中ti的效果；

               需要人工鼠标去点击这个TabItem才能让其正真选中并且呈现CaseSheetView

            */
            Style tabStyle = (Style)this.FindResource("ZetaTabItemStyle");
            ti.Style = tabStyle;

            DataTemplate tabheaderStyle = (DataTemplate)this.FindResource("ZetaTabItemHeaderTemplate");
            ti.HeaderTemplate = tabheaderStyle;

            CaseSheetView csv = new CaseSheetView();
            ti.Content = csv;
           
            ti.IsSelected = false;
            string sHeader = "新开案_1";
            ti.Width = 120;
            ti.Header = sHeader;
           
            int iindex = Zeta_tabWork.Items.Add(ti);
            Zeta_tabWork.SelectedItem = ti;
     
        }

2.下面这样写，就会正常显示：

        private void CaseSheetNew_Click(object sender, RoutedEventArgs e)
        {
            //Zeta_tabWork 为TabControl ;CaseSheetView 为UserControl的View
            TabItem ti = new TabItem();

            DataTemplate tabheaderStyle = (DataTemplate)this.FindResource("ZetaTabItemHeaderTemplate");
            ti.HeaderTemplate = tabheaderStyle;

            CaseSheetView csv = new CaseSheetView();
            ti.Content = csv;
           
            ti.IsSelected = false;
            string sHeader = "新开案_1";
            ti.Width = 120;
            ti.Header = sHeader;
           
            int iindex = Zeta_tabWork.Items.Add(ti);
            Zeta_tabWork.SelectedItem = ti;

            /*下面这两句在这个位置的话，即在 Zeta_tabWork.SelectedItem = ti 之后，选中ti的才正常

             即直接就会展示了CaseSheetView ！！！

            */
            Style tabStyle = (Style)this.FindResource("ZetaTabItemStyle");
            ti.Style = tabStyle;

     
        }

对比上面的代码行的先后顺序，确定是样式“ZetaTabItemStyle” 导致问题的产生，现在将样式ZetaTabItemStyle贴出下，请高手参详下是哪个细节的问题导致如此的：

   <Style  x:Key="ZetaTabItemStyle"  TargetType ="{x:Type TabItem }">
        <Setter Property="Foreground" Value="{StaticResource BaseColor10Key}"/>
        <Setter Property="Background" Value="{StaticResource BaseColor7Key}"/>
        <Setter Property="BorderBrush" Value="{StaticResource BaseColor4Key}"/>
        <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}"/>
        <Setter Property="ToolTip" Value="{Binding ToolTip}"/>
        <Setter Property="Padding" Value="2,1,2,1"/>
        <Setter Property="Margin" Value="2,3,-15,-1"/>

        <Setter Property ="Template">
            <Setter.Value>
                <ControlTemplate TargetType ="{x:Type TabItem }">
                    <Grid Height="32"  SnapsToDevicePixels="true">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="20"/>
                            <ColumnDefinition Width="*"/>
                        </Grid.ColumnDefinitions>
                        <ZetaBase:SplineBorder
                                            x:Name="splineBd"
                                            Fill="{TemplateBinding Background}"
                                            Stroke="{TemplateBinding BorderBrush}"
                                            BottomBorderMargin="0.5"/>

                        <Border x:Name="Bd" Grid.Column="1"
                           BorderBrush="{TemplateBinding BorderBrush}"
                                       BorderThickness="0,1,1,0"
                                                CornerRadius="0,2,0,0">
                            <Border  x:Name="BdInternal"
                           Background="{TemplateBinding Background}"
                           Padding="{TemplateBinding Padding}">
                                <ContentPresenter    x:Name="Content"
                            ContentSource="Header"
                                                    HorizontalAlignment="{Binding HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"
                                                    VerticalAlignment="{Binding VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"
                                                    RecognizesAccessKey="True"
                                                    SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                            </Border>
                        </Border>
                        <!--
                                 This represents the Close-button.
                           
                                 The Command-binding that we create here refers to the Window's
                                 DataContext (which, for the sample, is the window's code-behind);
                                 In order for the Command to be able to determine which TabItem the
                                 button belongs to, a relative binding will do the trick (i.e.,
                                 (bubble up to the parent TabItem).Margin="-7,2,7,5" Content.DataContext-->

                        <Button x:Name="cmdTabItemCloseButton"
                                     Style="{StaticResource TabItemCloseButtonStyle}"
                                        VerticalAlignment="Top"
                                        HorizontalAlignment="Right"                                   
                                     Command="{Binding Path=CloseTabItemCommand}"
                                     CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type TabItem}}}"
                                     Grid.Column="1"
                                        Visibility="Hidden"
                                        Margin="0,2,2,0"
                                    Padding="-1"                               
                                     />
                    </Grid >
                    <ControlTemplate.Triggers>
                        <DataTrigger Binding="{Binding Path=IsSelected}" Value="True">
                            <Setter Property="Visibility" Value="Visible" TargetName="cmdTabItemCloseButton"  />
                        </DataTrigger>
                        <DataTrigger Binding="{Binding Path=IsActive}" Value="True">
                            <Setter Property="Visibility" Value="Visible" TargetName="cmdTabItemCloseButton"  />
                        </DataTrigger>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter Property="Visibility" Value="Visible" TargetName="cmdTabItemCloseButton"  />
                            <Setter Property="Margin" Value="2,1,-15,-1"/>
                        </Trigger>
                        <DataTrigger Binding="{Binding Path=CanClose}" Value="False">
                            <Setter Property="Visibility" Value="Collapsed" TargetName="cmdTabItemCloseButton"  />
                        </DataTrigger>
                         <Trigger Property="IsSelected"  Value="True">
                            <Setter Property="Panel.ZIndex" Value="100" />
                            <Setter Property="BorderBrush"      Value="{DynamicResource BaseColor5Key}" />
                            <Setter Property="Background"       Value="{DynamicResource BaseColor6Key}" />
                            <Setter Property="Margin" Value="-1,-1,-15,-1"/>
                            <Setter Property="Margin" TargetName="BdInternal" Value="0,0,0,-1"/>
                            <Setter Property="Margin" TargetName="splineBd" Value="0,0,0,-1.0"/>
                            <Setter Property="BottomBorderMargin" TargetName="splineBd" Value="1.5"/>
                            <Setter Property="FontWeight" Value="Bold"/>
                            <Setter Property="Visibility" Value="Visible" TargetName="cmdTabItemCloseButton"  />
                        </Trigger>
                        <MultiTrigger>
                            <MultiTrigger.Conditions>
                                <Condition Property="IsMouseOver" Value="True"/>
                                <Condition Property="IsSelected" Value="False"/>
                            </MultiTrigger.Conditions>
                            <Setter Property="BorderBrush" Value="{DynamicResource BaseColor14Key}"/>
                            <Setter Property="Background" Value="{DynamicResource BaseColor17Key}"/>
                            <Setter Property="Panel.ZIndex" Value="0" />
                        </MultiTrigger>
                        <Trigger Property="IsEnabled" Value="False">
                            <Setter Property="BorderBrush" Value="{DynamicResource BaseColor13Key}"/>
                            <Setter Property="Background" Value="{DynamicResource BaseColor9Key}"/>
                            <Setter Property="Foreground" Value="{DynamicResource GrayTextBrushKey}"/>
                        </Trigger>
                    </ControlTemplate.Triggers>

                </ControlTemplate >

            </Setter.Value >

        </Setter >

    </Style >

Answer 1

更正确的写法应该是这样的：

       private void CaseSheetNew_Click(object sender, RoutedEventArgs e)
        {
            //Zeta_tabWork 为TabControl ;CaseSheetView 为UserControl的View
            TabItem ti = new TabItem();

            CaseSheetView csv = new CaseSheetView();
            ti.Content = csv;
           
            ti.IsSelected = false;
            string sHeader = "新开案_1";
            ti.Width = 120;
            ti.Header = sHeader;
           
            int iindex = Zeta_tabWork.Items.Add(ti);

            DataTemplate tabheaderStyle = (DataTemplate)this.FindResource("ZetaTabItemHeaderTemplate");
            ti.HeaderTemplate = tabheaderStyle;

            Style tabStyle = (Style)this.FindResource("ZetaTabItemStyle");
            ti.Style = tabStyle;

            Zeta_tabWork.SelectedItem = ti;
     
        }

原因：TabItem只有被加入到TabControl中，再应用样式或者模板才会正常起作用！！！！！！

Answer 2

您好，

根据您提供的代码，我制作了简单的Demo进行测试，发现 样式“ZetaTabItemStyle” 中

<Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}"/>

这个属性设置有问题，您这样的绑定可能导致了此TabItem无法被选中，UserControl的View就无法被正常显示。
我按照您的第一段代码进行了修改：

private void Window_Loaded(object sender, RoutedEventArgs e)
{
            //Zeta_tabWork 为TabControl ;CaseSheetView 为UserControl的View
            TabItem ti = new TabItem();

            Style tabStyle = (Style)this.FindResource("ZetaTabItemStyle");
            ti.Style = tabStyle;

            DataTemplate tabheaderStyle = (DataTemplate)this.FindResource("ZetaTabItemHeaderTemplate");
            ti.HeaderTemplate = tabheaderStyle;

            UserControl1 uc = new UserControl1();
            ti.Content = uc;

            ti.IsSelected = false;
            string sHeader = "新开案_1";
            ti.Width = 120;
            ti.Header = sHeader;

            int iindex = Zeta_tabWork.Items.Add(ti);
            Zeta_tabWork.SelectedItem = ti;

}

XAML中自己定义了DataTemplate "ZetaTabItemHeaderTemplate", 下图左侧为使用您的ZetaTabItemStyle后运行截图，右侧为注释那段代码(Property="IsSelected")后的显示效果:

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