能否不创建自定义控件来扩展System.Windows.Controls.Button？

完全可以不用创建自定义控件，通过**附加依赖属性（Attached Dependency Property）**给标准System.Windows.Controls.Button添加你需要的ButtonStyle枚举属性，结合样式触发器就能实现不同外观的按钮复用。

1. 定义枚举与附加属性 #

先创建一个静态类来承载附加属性和枚举类型：

public enum ButtonShapeStyle
{
    Square,
    Rounded,
    Circular
}

public static class ButtonExtensions
{
    public static readonly DependencyProperty ShapeStyleProperty =
        DependencyProperty.RegisterAttached(
            "ShapeStyle",
            typeof(ButtonShapeStyle),
            typeof(ButtonExtensions),
            new PropertyMetadata(ButtonShapeStyle.Square));

    public static void SetShapeStyle(DependencyObject element, ButtonShapeStyle value)
    {
        element.SetValue(ShapeStyleProperty, value);
    }

    public static ButtonShapeStyle GetShapeStyle(DependencyObject element)
    {
        return (ButtonShapeStyle)element.GetValue(ShapeStyleProperty);
    }
}

2. 编写带触发器的Button样式 #

在资源字典（或窗口/控件的Resources节点）中定义Button的基础样式，通过触发器监听附加属性变化，动态调整按钮外观：

<Style TargetType="Button">
    <Setter Property="Padding" Value="8,4"/>
    <Setter Property="Background" Value="#FF0078D7"/>
    <Setter Property="Foreground" Value="White"/>
    <Setter Property="BorderThickness" Value="0"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="Button">
                <Border x:Name="buttonBorder" 
                        Background="{TemplateBinding Background}"
                        CornerRadius="0">
                    <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center"/>
                </Border>
                <ControlTemplate.Triggers>
                    <Trigger Property="local:ButtonExtensions.ShapeStyle" Value="Square">
                        <Setter TargetName="buttonBorder" Property="CornerRadius" Value="0"/>
                    </Trigger>
                    <Trigger Property="local:ButtonExtensions.ShapeStyle" Value="Rounded">
                        <Setter TargetName="buttonBorder" Property="CornerRadius" Value="4"/>
                    </Trigger>
                    <Trigger Property="local:ButtonExtensions.ShapeStyle" Value="Circular">
                        <Setter TargetName="buttonBorder" Property="CornerRadius" Value="100"/>
                    </Trigger>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter TargetName="buttonBorder" Property="Background" Value="#FF005A9E"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

3. 实际使用示例 #

在XAML中直接给原生Button设置附加属性即可：

<!-- 方形按钮 -->
<Button Content="方形按钮" local:ButtonExtensions.ShapeStyle="Square"/>

<!-- 圆角按钮 -->
<Button Content="圆角按钮" local:ButtonExtensions.ShapeStyle="Rounded"/>

<!-- 圆形按钮（建议固定宽高） -->
<Button Content="圆形" local:ButtonExtensions.ShapeStyle="Circular" Width="60" Height="60"/>

方案优势 #

• 完全基于原生Button，保留其所有内置功能与事件
• 附加属性全局可用，所有Button控件都能直接复用该逻辑
• 样式与逻辑分离，后续修改外观只需调整模板或触发器即可

如果后续需要更复杂的自定义逻辑（比如专属事件、特殊布局），再考虑创建自定义控件也不迟，当前需求用附加属性完全可以满足。

内容的提问来源于stack exchange，提问作者Richard Gale