C# WPF圆形边框按钮响应单击颜色更改

我的WPF应用程序（MVVM模式）上有一个按钮，它对单击事件作出响应。基本上，如果单击此按钮，其背景将变为浅绿色（默认颜色为浅灰色）。我已经使用以下代码实现了所需的行为：

<Button Grid.Column="2" Grid.Row="6" Grid.ColumnSpan="3" Grid.RowSpan="2" Content="{Binding FirstSchedule.Message}" Command="{Binding FirstScheduleButtonClick}">
    <Button.Style>
        <Style TargetType="Button">
            <Setter Property="Background" Value="LightGray"></Setter>
            <Style.Triggers>
                <DataTrigger Binding="{Binding FirstScheduleButtonSelected}" Value="True">
                    <Setter Property="Background" Value="LightGreen"></Setter>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Button.Style>
</Button>

现在我需要使这个按钮的边框变圆。我已经尝试过这个解决方案，结果是：

<Button Grid.Column="2" Grid.Row="6" Grid.ColumnSpan="3" Grid.RowSpan="2" Content="{Binding FirstSchedule.Message}" Command="{Binding FirstScheduleButtonClick}">
    <Button.Style>
        <Style TargetType="Button">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="Button">
                        <Border CornerRadius="15" Background="LightGray" BorderThickness="1" Padding="2">
                            <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
            <Setter Property="Background" Value="LightGray"></Setter>
            <Style.Triggers>
                <DataTrigger Binding="{Binding FirstScheduleButtonSelected}" Value="True">
                    <Setter Property="Background" Value="LightGreen"></Setter>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Button.Style>
</Button>

现在我的边框实际上是圆形的，但当我单击按钮时，它不会变成绿色

问：我如何修改此按钮，使其边框变圆，并保持单击时更改其颜色的功能？

以下是我要做的：

<Window.Resources>
    <!-- ... -->

    <Style x:Key="GreenToggleButtonStyle" TargetType="ToggleButton">
        <Setter Property="Background" Value="LightGray" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="ToggleButton">
                    <Border 
                        CornerRadius="15" 
                        Background="{TemplateBinding Background}" 
                        BorderThickness="1" 
                        Padding="2"
                        >
                        <ContentPresenter 
                            HorizontalAlignment="Center" 
                            VerticalAlignment="Center" 
                            />
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsChecked" Value="True">
                            <Setter 
                                Property="Background"
                                Value="LightGreen"
                                />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <!-- ... -->
</Window.Resources>

---

工作起来很有魅力！非常感谢：）

<Window.Resources>
    <!-- ... -->

    <Style x:Key="GreenToggleButtonStyle" TargetType="ToggleButton">
        <Setter Property="Background" Value="LightGray" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="ToggleButton">
                    <Border 
                        CornerRadius="15" 
                        Background="{TemplateBinding Background}" 
                        BorderThickness="1" 
                        Padding="2"
                        >
                        <ContentPresenter 
                            HorizontalAlignment="Center" 
                            VerticalAlignment="Center" 
                            />
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsChecked" Value="True">
                            <Setter 
                                Property="Background"
                                Value="LightGreen"
                                />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <!-- ... -->
</Window.Resources>

<ToggleButton 
    Grid.Column="2" 
    Grid.Row="6" 
    Grid.ColumnSpan="3" 
    Grid.RowSpan="2" 
    Content="{Binding FirstSchedule.Message}" 
    IsChecked="{Binding FirstScheduleButtonSelected}"
    Style="{StaticResource GreenToggleButtonStyle}"
    />