c# - ComboBox 元素的样式

Question

我有一个 ComboBox绑定(bind)到 ObservableCollection<ElementType>收藏。我想要不可选择的分隔符，其中 Name 和 Type 属性都设置为 null。当名称设置为字符串且类型为空时，我希望它是一个不可选择的标题/标题。否则，我希望这些元素是可选择的元素，但有一点余量。

这是我到目前为止的位置:

我的两个问题是:

• 所选项目显示为具有完整 namespace 的 ElementType 对象，而不是名称字符串。
• 已启用元素的突出显示不再显示在 MouseOver 上。

XAML:

<ComboBox Grid.Column="1" Grid.Row="2" Style="{StaticResource ElementTypeComboBoxStyle}"
            ItemsSource="{Binding Path=Element.ElementTypeList}"
            SelectedItem="{Binding Path=Element.SelectedElementType}">
    <ComboBox.Resources>
        <converters:NullToBooleanConverter x:Key="NullToBooleanConverter" />
    </ComboBox.Resources>
    <ComboBox.ItemContainerStyle>
        <Style TargetType="{x:Type ComboBoxItem}">
            <Style.Triggers>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding Path=Name, Converter={StaticResource NullToBooleanConverter}}" Value="True" />
                        <Condition Binding="{Binding Path=Type, Converter={StaticResource NullToBooleanConverter}}" Value="True" />
                    </MultiDataTrigger.Conditions>
                    <Setter Property="IsEnabled" Value="False" />
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate TargetType="{x:Type ComboBoxItem}">
                                <Separator HorizontalAlignment="Stretch" />
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding Path=Name, Converter={StaticResource NullToBooleanConverter}}" Value="False" />
                        <Condition Binding="{Binding Path=Type, Converter={StaticResource NullToBooleanConverter}}" Value="True" />
                    </MultiDataTrigger.Conditions>
                    <Setter Property="IsEnabled" Value="False" />
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate TargetType="{x:Type ComboBoxItem}">
                                <TextBlock Text="{Binding Path=Name}" />
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding Path=Name, Converter={StaticResource NullToBooleanConverter}}" Value="False" />
                        <Condition Binding="{Binding Path=Type, Converter={StaticResource NullToBooleanConverter}}" Value="False" />
                    </MultiDataTrigger.Conditions>
                    <Setter Property="IsEnabled" Value="True" />
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate TargetType="{x:Type ComboBoxItem}">
                                <TextBlock Text="{Binding Path=Name}" Margin="10,0,0,0" />
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </MultiDataTrigger>
            </Style.Triggers>
        </Style>
    </ComboBox.ItemContainerStyle>
</ComboBox>

C#:

public class ElementType {
    public ElementType(string name, Type type) {
        Name = name;
        Type = type;
    }
    public string Name { get; private set; }
    public Type Type { get; private set; }
}

private static ObservableCollection<ElementType> _elementTypeList = new ObservableCollection<ElementType> {
    // Controls
    new ElementType("Controls:", null),
    new ElementType("Analog Output Slider", typeof(AnalogOutputSliderControl)),
    new ElementType("Digital Output Button", typeof(DigitalOutputButtonControl)),

    new ElementType(null, null),  // Separator

    // Indicators
    new ElementType("Indicators:", null),
    new ElementType("Numeric Value", typeof(NumericValueIndicator)),
    new ElementType("ROV Illustration", typeof(RovIllustration)),
    new ElementType("Trend Graph", typeof(TrendGraphIndicator)),

    new ElementType(null, null),  // Separator

    // Generic element
    new ElementType("None", typeof(Element))
};
[XmlIgnore]
public static ObservableCollection<ElementType> ElementTypeList { get { return _elementTypeList; } }

Answer 1

我选择不使用模板选择器，因为我认为它对我的需求来说有点重。我在 XAML 中找到了解决该问题的方法，得到了以下结果。它也适用于箭头键，因为分隔符和标题被禁用。唯一的“问题”是标题的灰色，但我暂时保留它。

XAML:

<ComboBox Grid.Column="1" Grid.Row="2" Style="{StaticResource ElementTypeComboBoxStyle}"
            ItemsSource="{Binding Path=Element.ElementTypeList}"
            SelectedItem="{Binding Path=Element.SelectedElementType}">
    <ComboBox.Resources>
        <converters:NullToBooleanConverter x:Key="NullToBooleanConverter" />
    </ComboBox.Resources>
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Path=Name}" />
        </DataTemplate>
    </ComboBox.ItemTemplate>
    <ComboBox.ItemContainerStyle>
        <Style TargetType="{x:Type ComboBoxItem}">
            <Setter Property="IsEnabled" Value="False" />
            <Style.Triggers>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding Path=Name, Converter={StaticResource NullToBooleanConverter}}" Value="True" />
                        <Condition Binding="{Binding Path=Type, Converter={StaticResource NullToBooleanConverter}}" Value="True" />
                    </MultiDataTrigger.Conditions>
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate TargetType="{x:Type ComboBoxItem}">
                                <Separator HorizontalAlignment="Stretch" />
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </MultiDataTrigger>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding Path=Name, Converter={StaticResource NullToBooleanConverter}}" Value="False" />
                        <Condition Binding="{Binding Path=Type, Converter={StaticResource NullToBooleanConverter}}" Value="False" />
                    </MultiDataTrigger.Conditions>
                    <Setter Property="IsEnabled" Value="True" />
                    <Setter Property="Padding" Value="10,0,0,0" />
                </MultiDataTrigger>                            
            </Style.Triggers>
        </Style>
    </ComboBox.ItemContainerStyle>
</ComboBox>