当IsEnabled=False时，WPF按钮背景

Question

我试图在按钮未启用时为其设置样式，以便Background LinearGradientBrush与启用时为按钮设置的样式相似。我尝试过触发器，但似乎只有文本颜色在改变：

<Application x:Class="RSPolar.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
        <!--Windows style-->
        <Style TargetType="Window">
            <Setter Property="Background">
                <Setter.Value>
                    <LinearGradientBrush  StartPoint="0,0" EndPoint="0,1">
                        <GradientStop Color="Gray" Offset="1" />
                        <GradientStop Color="DarkGray" Offset="0.92" />
                        <GradientStop Color="Gray" Offset="0.9" />
                        <GradientStop Color="LightGray" Offset="0.88" />
                        <GradientStop Color="WhiteSmoke" Offset="0" />
                    </LinearGradientBrush>
                </Setter.Value>
            </Setter>
        </Style>
        <!--Buttons style-->
        <Style TargetType="Button">
            <Setter Property="ContentTemplate">
                <Setter.Value>
                    <DataTemplate>
                        <TextBlock FontWeight="Bold" FontSize="48" Foreground="#00FF00" Text="{Binding Path=Content,RelativeSource={RelativeSource AncestorType={x:Type Button}}}">
                            <TextBlock.Effect>
                                <DropShadowEffect BlurRadius="1" Color="DarkGray" ShadowDepth="1" Direction="120"/>
                            </TextBlock.Effect>
                        </TextBlock>
                    </DataTemplate>
                </Setter.Value>
            </Setter>
            <Setter Property="Background">
                <Setter.Value>
                    <LinearGradientBrush  StartPoint="0,0" EndPoint="0,1">
                        <GradientStop Color="Gray" Offset="1" />
                        <GradientStop Color="DarkGray" Offset="0.52" />
                        <GradientStop Color="Gray" Offset="0.5" />
                        <GradientStop Color="LightGray" Offset="0.48" />
                        <GradientStop Color="WhiteSmoke" Offset="0" />
                    </LinearGradientBrush>
                </Setter.Value>
            </Setter>
            <Setter Property="Button.Effect">
                <Setter.Value>
                    <DropShadowEffect Color="Black" Direction="320" ShadowDepth="5" BlurRadius="10" Opacity="0.5" />
                </Setter.Value>
            </Setter>
            <Setter Property="Button.Effect">
                <Setter.Value>
                    <BlurEffect Radius="1"></BlurEffect>
                </Setter.Value>
            </Setter>
            <Style.Triggers>
                <Trigger Property="IsEnabled" Value="False">
                    <Setter Property="ContentTemplate">
                        <Setter.Value>
                            <DataTemplate>
                                <TextBlock FontWeight="Bold" FontSize="48" Foreground="#FF0000" Text="{Binding Path=Content,RelativeSource={RelativeSource AncestorType={x:Type Button}}}">
                                    <TextBlock.Effect>
                                        <DropShadowEffect BlurRadius="1" Color="DarkGray" ShadowDepth="1" Direction="120"/>
                                    </TextBlock.Effect>
                                </TextBlock>
                            </DataTemplate>
                        </Setter.Value>
                    </Setter>
                    <Setter Property="Background">
                        <Setter.Value>
                            <LinearGradientBrush  StartPoint="0,0" EndPoint="0,1">
                                <GradientStop Color="Gray" Offset="1" />
                                <GradientStop Color="DarkGray" Offset="0.52" />
                                <GradientStop Color="Gray" Offset="0.5" />
                                <GradientStop Color="LightGray" Offset="0.48" />
                                <GradientStop Color="WhiteSmoke" Offset="0" />
                            </LinearGradientBrush>
                        </Setter.Value>
                    </Setter>
                </Trigger>
            </Style.Triggers>
        </Style>
    </Application.Resources>
</Application>

Answer 1

您不应该定义ContentTemplate属性。如果您想更改按钮的外观，您应该定义Template属性，并将您的Trigger添加到您在那里定义的ControlTemplate中。

如果您阅读MSDN上的"通过创建控件模板自定义现有控件的外观"页面，也许会有所帮助？您还可以在MSDN上的ControlTemplate类页面中找到使用ControlTemplate.Triggers的示例。

然而，这里有一个简单的例子：

在Resources:中

<ControlTemplate x:Key="ExampleButton" TargetType="{x:Type Button}">
    <Border Background="LightGreen" BorderBrush="Black" BorderThickness="1" 
        CornerRadius="5" x:Name="Border" Padding="10">
        <ContentPresenter />    
    </Border>
    <ControlTemplate.Triggers>
        <Trigger Property="IsEnabled" Value="False">
            <Setter TargetName="Border" Property="Background" Value="LightBlue" />
        </Trigger>
    </ControlTemplate.Triggers>
</ControlTemplate>

在XAML页面中：

<StackPanel HorizontalAlignment="Center" VerticalAlignment="Center">
    <Button Template="{StaticResource ExampleButton}" Content="Click me" />
    <Button Template="{StaticResource ExampleButton}" Content="Click me" 
        IsEnabled="False" />
</StackPanel>

---

更新>>>

您只需要将"普通"Background值替换为LinearGradientBrush，如您的示例中所示：

在Resources:中

<ControlTemplate x:Key="ExampleButton" TargetType="{x:Type Button}">
    <Border BorderBrush="Black" BorderThickness="1" 
        CornerRadius="5" x:Name="Border" Padding="10">
        <Border.Background>
            <LinearGradientBrush  StartPoint="0,0" EndPoint="0,1">
                <GradientStop Color="Gray" Offset="1" />
                <GradientStop Color="DarkGray" Offset="0.52" />
                <GradientStop Color="Gray" Offset="0.5" />
                <GradientStop Color="LightGray" Offset="0.48" />
                <GradientStop Color="WhiteSmoke" Offset="0" />
            </LinearGradientBrush>
        </Border.Background>
        <ContentPresenter />
    </Border>
    <ControlTemplate.Triggers>
        <Trigger Property="IsEnabled" Value="False">
            <Setter TargetName="Border" Property="Background">
                <Setter.Value>
                    <LinearGradientBrush  StartPoint="0,0" EndPoint="0,1">
                        <GradientStop Color="Gray" Offset="1" />
                        <GradientStop Color="DarkGray" Offset="0.52" />
                        <GradientStop Color="Gray" Offset="0.5" />
                        <GradientStop Color="LightGray" Offset="0.48" />
                        <GradientStop Color="WhiteSmoke" Offset="0" />
                    </LinearGradientBrush>
                </Setter.Value>
            </Setter>
        </Trigger>
    </ControlTemplate.Triggers>
</ControlTemplate>

为什么目标边框设置按钮的背景颜色？它不应该改变边框的颜色吗？

Button的Background是Border的Background。