如何更改 Combobox SelectedItem 的字体系列？

Question

我有 ComboBox 的样式。并为其设置 Font-family。

为项目设置字体，但不为选定项目设置。

<DataTemplate x:Key="SelectionBoxTextTemplate">
     <TextBlock FontFamily="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ComboBox}}, Path=FontFamily}" Text="{Binding}"/>
</DataTemplate>
<Style x:Key="{x:Type ComboBox}" TargetType="{x:Type ComboBox}">
    <Setter Property="MinWidth" Value="120"/>
    <Setter Property="FontFamily" Value="{StaticResource IranSansFontFamily}"/>
     <Setter Property="Template">
        <Setter.Value>
           <ControlTemplate TargetType="{x:Type ComboBox}">
              <Grid>
                 <ToggleButton
                    Name="ToggleButton"
                    Grid.Column="2"
                    ClickMode="Press"
                    Focusable="false"
                    IsChecked="{Binding Path=IsDropDownOpen,Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}"
                    Template="{StaticResource ComboBoxToggleButton}">
                 </ToggleButton>
                 <ContentPresenter
                    Name="ContentSite"
                    HorizontalAlignment="Left"
                    Margin="3,3,23,3"
                    VerticalAlignment="Center"
                    Content="{TemplateBinding SelectionBoxItem}"
                    ContentTemplate="{StaticResource SelectionBoxTextTemplate}"
                    ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}"
                    IsHitTestVisible="False"/>

Answer 1

您需要使用 IsSelected 属性上的触发器。有关示例，请参阅this answer。它适用于 ListBox，但也适用于 ComboBox。

Answer 2

您可以使用自定义模板选择器，如下所示：

  public class ComboBoxItemTemplateSelector : DataTemplateSelector
    {
        public DataTemplate SelectedItemTemplate { get; set; }
        public DataTemplate ItemTemplate { get; set; }
        public override DataTemplate SelectTemplate(object item, DependencyObject container)
        {
            bool selected = false;
            FrameworkElement fe = container as FrameworkElement;
            if (fe != null)
            {
                DependencyObject parent = fe.TemplatedParent;
                if (parent != null)
                {
                    ComboBox cbo = parent as ComboBox;
                    if (cbo != null)
                        selected = true;
                }
            }
            if (selected)
                return SelectedItemTemplate;
            else
                return ItemTemplate;
        }
    }

在 xaml 中：

 <ComboBox Name="cb" Height="28">
            <ComboBox.ItemTemplateSelector>
                <local:ComboBoxItemTemplateSelector>
                    <local:ComboBoxItemTemplateSelector.ItemTemplate>
                        <DataTemplate>
                            <TextBlock Text="{Binding}" FontFamily="Comic Sans MS"/>
                        </DataTemplate>
                    </local:ComboBoxItemTemplateSelector.ItemTemplate>
                    <local:ComboBoxItemTemplateSelector.SelectedItemTemplate>
                        <DataTemplate>
                            <TextBlock Text="{Binding}" FontFamily="Arial Black"/>
                        </DataTemplate>
                    </local:ComboBoxItemTemplateSelector.SelectedItemTemplate>
                </local:ComboBoxItemTemplateSelector>
            </ComboBox.ItemTemplateSelector>
        </ComboBox>

结果：