如何在WPF中共享两个Button样式的ControlTemplate.Triggers？

方法1：提取通用触发器为独立资源 #

把鼠标悬停、按下、禁用等通用视觉状态触发器单独定义为资源，在所有需要的ControlTemplate中直接引用，避免重复编写代码。

实现步骤： #

1. 定义通用触发器资源

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <!-- 通用按钮视觉状态触发器集合 -->
    <TriggerCollection x:Key="CommonButtonTriggers">
        <Trigger Property="IsMouseOver" Value="True">
            <Setter Property="Background" Value="#FFBEE6FD"/>
            <Setter Property="BorderBrush" Value="#FF3C7FB1"/>
        </Trigger>
        <Trigger Property="IsPressed" Value="True">
            <Setter Property="Background" Value="#FFC4E5F6"/>
            <Setter Property="BorderBrush" Value="#FF2C628B"/>
        </Trigger>
        <Trigger Property="IsEnabled" Value="False">
            <Setter Property="Background" Value="#FFF4F4F4"/>
            <Setter Property="BorderBrush" Value="#FFADB2B5"/>
            <Setter Property="Foreground" Value="#FF838383"/>
        </Trigger>
        <Trigger Property="IsFocused" Value="True">
            <Setter Property="BorderBrush" Value="#FF3C7FB1"/>
        </Trigger>
    </TriggerCollection>
</ResourceDictionary>

2. 基础按钮样式引用通用触发器

<Style x:Key="winFormButton" TargetType="Button">
    <Setter Property="Background" Value="#FFFFFF"/>
    <Setter Property="BorderBrush" Value="#FF888888"/>
    <Setter Property="BorderThickness" Value="1"/>
    <Setter Property="Padding" Value="6,3"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="Button">
                <Border x:Name="border" 
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}"
                        CornerRadius="2">
                    <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                      VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                                      Margin="{TemplateBinding Padding}"/>
                </Border>
                <!-- 直接引用通用触发器 -->
                <ControlTemplate.Triggers>
                    <StaticResource ResourceKey="CommonButtonTriggers"/>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

3. 下拉按钮样式复用通用触发器

<Style x:Key="dropdownWinFormButton" TargetType="Button" BasedOn="{StaticResource winFormButton}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="Button">
                <Grid>
                    <Border x:Name="border" 
                            Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            CornerRadius="2">
                        <Grid>
                            <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                              VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                                              Margin="{TemplateBinding Padding}"/>
                            <!-- 下拉按钮特有的箭头元素 -->
                            <Path x:Name="arrow" HorizontalAlignment="Right" VerticalAlignment="Center"
                                  Margin="0,0,6,0" Width="8" Height="5"
                                  Data="M0,0 L8,0 L4,5 Z" Fill="{TemplateBinding Foreground}"/>
                        </Grid>
                    </Border>
                </Grid>
                <!-- 复用通用触发器，仅添加下拉按钮特有逻辑 -->
                <ControlTemplate.Triggers>
                    <StaticResource ResourceKey="CommonButtonTriggers"/>
                    <Trigger Property="IsPressed" Value="True">
                        <Setter TargetName="arrow" Property="Fill" Value="#FF2C628B"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

方法2：用附加属性封装触发器逻辑 #

如果触发器逻辑复杂，可将视觉状态切换逻辑封装到C#附加属性中，通过XAML绑定附加属性实现统一管理，无需在XAML中重复编写触发器。

实现步骤： #

1. 定义附加属性类

public static class ButtonVisualStateHelper
{
    public static readonly DependencyProperty UseCommonStatesProperty =
        DependencyProperty.RegisterAttached("UseCommonStates", typeof(bool), typeof(ButtonVisualStateHelper),
            new PropertyMetadata(false, OnUseCommonStatesChanged));

    public static void SetUseCommonStates(DependencyObject obj, bool value)
    {
        obj.SetValue(UseCommonStatesProperty, value);
    }

    public static bool GetUseCommonStates(DependencyObject obj)
    {
        return (bool)obj.GetValue(UseCommonStatesProperty);
    }

    private static void OnUseCommonStatesChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (d is not Button button || !(bool)e.NewValue) return;

        // 鼠标悬停触发器
        var mouseOverTrigger = new Trigger { Property = Button.IsMouseOverProperty, Value = true };
        mouseOverTrigger.Setters.Add(new Setter(Button.BackgroundProperty, Brushes.LightBlue));
        mouseOverTrigger.Setters.Add(new Setter(Button.BorderBrushProperty, Brushes.DarkBlue));

        // 按下状态触发器
        var pressedTrigger = new Trigger { Property = Button.IsPressedProperty, Value = true };
        pressedTrigger.Setters.Add(new Setter(Button.BackgroundProperty, Brushes.SkyBlue));
        pressedTrigger.Setters.Add(new Setter(Button.BorderBrushProperty, Brushes.MediumBlue));

        // 禁用状态触发器
        var disabledTrigger = new Trigger { Property = Button.IsEnabledProperty, Value = false };
        disabledTrigger.Setters.Add(new Setter(Button.BackgroundProperty, Brushes.LightGray));
        disabledTrigger.Setters.Add(new Setter(Button.BorderBrushProperty, Brushes.DarkGray));

        // 将触发器添加到按钮样式
        button.Style ??= new Style(typeof(Button));
        foreach (var trigger in new[] { mouseOverTrigger, pressedTrigger, disabledTrigger })
        {
            button.Style.Triggers.Add(trigger);
        }
    }
}

2. 在XAML中引用附加属性

<!-- 基础按钮样式 -->
<Style x:Key="winFormButton" TargetType="Button">
    <Setter Property="local:ButtonVisualStateHelper.UseCommonStates" Value="True"/>
    <!-- 其他样式设置和模板 -->
</Style>

<!-- 下拉按钮样式 -->
<Style x:Key="dropdownWinFormButton" TargetType="Button" BasedOn="{StaticResource winFormButton}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="Button">
                <!-- 自定义下拉按钮模板结构 -->
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

方法3：用VisualStateManager统一管理状态 #

将通用视觉状态封装为VisualStateGroup资源，在各个按钮模板中引用该状态组，通过VisualStateManager自动处理状态切换。

实现步骤： #

1. 定义通用视觉状态组资源

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <VisualStateGroup x:Key="CommonButtonVisualStates">
        <VisualState x:Name="Normal"/>
        <VisualState x:Name="MouseOver">
            <Storyboard>
                <ColorAnimation Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)"
                                To="#FFBEE6FD" Duration="0:0:0.1"/>
                <ColorAnimation Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)"
                                To="#FF3C7FB1" Duration="0:0:0.1"/>
            </Storyboard>
        </VisualState>
        <VisualState x:Name="Pressed">
            <Storyboard>
                <ColorAnimation Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)"
                                To="#FFC4E5F6" Duration="0:0:0.1"/>
                <ColorAnimation Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)"
                                To="#FF2C628B" Duration="0:0:0.1"/>
            </Storyboard>
        </VisualState>
        <VisualState x:Name="Disabled">
            <Storyboard>
                <ColorAnimation Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)"
                                To="#FFF4F4F4" Duration="0"/>
                <ColorAnimation Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)"
                                To="#FFADB2B5" Duration="0"/>
            </Storyboard>
        </VisualState>
    </VisualStateGroup>
</ResourceDictionary>

2. 在模板中引用状态组

<Style x:Key="winFormButton" TargetType="Button">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="Button">
                <Border x:Name="border" 
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}">
                    <VisualStateManager.VisualStateGroups>
                        <!-- 引用通用状态组 -->
                        <StaticResource ResourceKey="CommonButtonVisualStates"/>
                    </VisualStateManager.VisualStateGroups>
                    <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                      VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

<Style x:Key="dropdownWinFormButton" TargetType="Button" BasedOn="{StaticResource winFormButton}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="Button">
                <Border x:Name="border" 
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}">
                    <VisualStateManager.VisualStateGroups>
                        <!-- 复用通用状态组 -->
                        <StaticResource ResourceKey="CommonButtonVisualStates"/>
                    </VisualStateManager.VisualStateGroups>
                    <Grid>
                        <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                        <Path x:Name="arrow" Data="M0,0 L8,0 L4,5 Z" Fill="{TemplateBinding Foreground}"/>
                    </Grid>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

以上三种方法均能实现触发器逻辑的集中维护，后续修改视觉状态时仅需改动一处资源或代码，无需在多个样式中重复操作。

内容的提问来源于stack exchange，提问作者d365b