c# - 更改自定义 WPF ComboBox 的背景

Question

我有一个自定义 ComboBox，它应该对某些依赖属性的值使用react。 (例如验证)。现在，我只是找不到如何在 controltemplate 的触发器中更改组合框控件的背景...我可以更改下拉菜单，但还没有找到如何更改整个控件的背景.依赖属性设置正确，这里是 XAML:

  <ControlTemplate x:Key="ComboBoxToggleButton" TargetType="ToggleButton">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition />
            <ColumnDefinition Width="20" />
        </Grid.ColumnDefinitions>
        <Border
              x:Name="Border" 
              Grid.ColumnSpan="2"
              CornerRadius="2"
              Background="{StaticResource NormalBrush}"
              BorderBrush="{StaticResource NormalBorderBrush}"
              BorderThickness="1" />
        <Border 
              Grid.Column="0"
              CornerRadius="2,0,0,2" 
              Margin="1" 
              Background="{StaticResource WindowBackgroundBrush}" 
              BorderBrush="{StaticResource NormalBorderBrush}"
              BorderThickness="0,0,1,0" />
        <Path 
              x:Name="Arrow"
              Grid.Column="1"     
              Fill="{StaticResource GlyphBrush}"
              HorizontalAlignment="Center"
              VerticalAlignment="Center"
              Data="M 0 0 L 4 4 L 8 0 Z"/>
    </Grid>
    <ControlTemplate.Triggers>
        <Trigger Property="ToggleButton.IsMouseOver" Value="true">
            <Setter TargetName="Border" Property="Background" Value="{StaticResource DarkBrush}" />
        </Trigger>
        <Trigger Property="ToggleButton.IsChecked" Value="true">
            <Setter TargetName="Border" Property="Background" Value="{StaticResource PressedBrush}" />
        </Trigger>
        <Trigger Property="IsEnabled" Value="False">
            <Setter TargetName="Border" Property="Background" Value="{StaticResource DisabledBackgroundBrush}" />
            <Setter TargetName="Border" Property="BorderBrush" Value="{StaticResource DisabledBorderBrush}" />
            <Setter Property="Foreground" Value="{StaticResource DisabledForegroundBrush}"/>
            <Setter TargetName="Arrow" Property="Fill" Value="{StaticResource DisabledForegroundBrush}" />
        </Trigger>
    </ControlTemplate.Triggers>
</ControlTemplate>

<ControlTemplate x:Key="ComboBoxTextBox" TargetType="TextBox">
    <Border x:Name="PART_ContentHost" Focusable="False" Background="{TemplateBinding Background}" />

</ControlTemplate>

<Style x:Key="{x:Type local:ErgoDentComboBox}" TargetType="ComboBox" BasedOn="ComboBox">
    <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="MinWidth" Value="120"/>
    <Setter Property="MinHeight" Value="20"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type local:ErgoDentComboBox}">
                <Grid>
                    <ToggleButton 
                        Name="ToggleButton" 
                        Template="{StaticResource ComboBoxToggleButton}" 
                        Grid.Column="2" 
                        Focusable="false"
                        IsChecked="{Binding Path=IsDropDownOpen,Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}"
                        ClickMode="Press">
                    </ToggleButton>
                    <ContentPresenter
                        Name="ContentSite"
                        IsHitTestVisible="False" 
                        Content="{TemplateBinding SelectionBoxItem}"
                        ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}"
                        ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}"
                        Margin="3,3,23,3"
                        VerticalAlignment="Center"
                        HorizontalAlignment="Left" />
                    <TextBox x:Name="PART_EditableTextBox"
                            Style="{x:Null}" 
                            Template="{StaticResource ComboBoxTextBox}" 
                            HorizontalAlignment="Left" 
                            VerticalAlignment="Center" 
                            Margin="3,3,23,3"
                            Focusable="True" 
                          Background="Transparent"
                            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="{StaticResource WindowBackgroundBrush}"
                                BorderThickness="1"
                                BorderBrush="{StaticResource SolidBorderBrush}"/>
                            <ScrollViewer Margin="4,6,4,6" SnapsToDevicePixels="True">
                                <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
                            </ScrollViewer>
                        </Grid>
                    </Popup>
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="HasItems" Value="false">
                        <Setter TargetName="DropDownBorder" Property="MinHeight" Value="95"/>
                    </Trigger>
                    <Trigger Property="IsEnabled" Value="false">
                        <Setter Property="Foreground" Value="{StaticResource DisabledForegroundBrush}"/>
                    </Trigger>
                    <Trigger Property="IsGrouping" Value="true">
                        <Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
                    </Trigger>
                    <Trigger SourceName="Popup" Property="Popup.AllowsTransparency" Value="true">
                        <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="4"/>
                        <Setter TargetName="DropDownBorder" Property="Margin" Value="0,2,0,0"/>
                    </Trigger>
                    <Trigger Property="IsEditable"
           Value="true">
                        <Setter Property="IsTabStop" Value="false"/>
                        <Setter TargetName="PART_EditableTextBox" Property="Visibility"    Value="Visible"/>
                        <Setter TargetName="ContentSite" Property="Visibility" Value="Hidden"/>
                    </Trigger>
                    <!-- THIS ISN'T WORKING -->
                    <Trigger Property="IsValidationError" Value="False">
                        <Setter Property="BorderBrush" Value="DarkGreen" />
                        <Setter Property="Background" Value="Green" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
    <Style.Triggers>
    </Style.Triggers>
</Style>

在控件的代码中我可以轻松设置背景，我该如何在触发器中执行此操作？

谢谢

丹尼

Answer 1

对于您真正想要更改的内容，我仍然有些困惑。我假设它是 ToggleButton 背景。

由于 ToggleButton 有一个单独的 ControlTemplate，如果您想将颜色从 ComboBox 模板触发器传递到 ToggleButton 模板，我建议您使用 TemplateBinding。同样的方法也适用于更改边框颜色。

在您的 ComboBox 模板中:

<ToggleButton Name="ToggleButton" Template="{StaticResource ComboBoxToggleButton}" 
              Grid.Column="2" Focusable="false" ClickMode="Press"
              IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
              Background="{StaticResource WindowBackgroundBrush}"/> <!-- notice this line -->


 <Trigger Property="IsValidationError" Value="False">
     <Setter TargetName="DropDownBorder" Property="Background" Value="Yellow" /> <!-- changing dropdown background -->
     <Setter TargetName="ToggleButton" Property="Background" Value="Yellow" /> <!-- changing togglebutton background -->
 </Trigger>

在您的 ToggleButton 模板中:

 <Border Grid.Column="0" CornerRadius="2,0,0,2" Margin="1" 
         BorderBrush="{StaticResource NormalBorderBrush}" BorderThickness="0,0,1,0"
         Background="{TemplateBinding Background}" /> <!-- notice this line -->