Question

我在WPF中遇到了Styles。当用户将鼠标悬停在按钮上时，我需要更改背景渐变，但我无法弄清楚如何进行更改。这是我到目前为止的代码：

    <Style x:Key="Button_Green" TargetType="{x:Type Button}">
    <Setter Property="FontSize" Value="11" />
    <Setter Property="Foreground" Value="White"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">
                <Border CornerRadius="2" BorderBrush="#387f38" BorderThickness="1">
                    <Border.Background>
                        <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                            <GradientStop Color="#FF5BB75B" Offset="0" />
                            <GradientStop Color="#FF449B44" Offset="1" />
                        </LinearGradientBrush>
                    </Border.Background>
                    <ContentPresenter x:Name="ButtonContentPresenter" VerticalAlignment="Center" HorizontalAlignment="Center"/>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
    <Style.Triggers>
        <Trigger Property="IsMouseOver" Value="True">
            <Setter Property="Background">
                <Setter.Value>
                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                        <GradientStop Color="#FF5BB75B" Offset="0" />
                        <GradientStop Color="#FF398239" Offset="1" />
                    </LinearGradientBrush>
                </Setter.Value>
            </Setter>
            <Setter Property="Cursor" Value="Hand" />
        </Trigger>
    </Style.Triggers>
</Style>

鼠标光标正确更改，但背景渐变不会改变。

Answer 1

您需要将setter的目标设置为Border中定义的ControlTemplate元素。目前，它定位Background本身的Button属性，该属性由您的自定义ControlTemplate隐藏。

<Style x:Key="Button_Green" TargetType="{x:Type Button}">
<Setter Property="FontSize" Value="11" />
<Setter Property="Foreground" Value="White"/>
<Setter Property="Template">
    <Setter.Value>
        <ControlTemplate TargetType="{x:Type Button}">
            <Border x:Name="MyBackgroundElement" CornerRadius="2" BorderBrush="#387f38" BorderThickness="1">
                <Border.Background>
                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                        <GradientStop Color="#FF5BB75B" Offset="0" />
                        <GradientStop Color="#FF449B44" Offset="1" />
                    </LinearGradientBrush>
                </Border.Background>
                <ContentPresenter x:Name="ButtonContentPresenter" VerticalAlignment="Center" HorizontalAlignment="Center"/>
            </Border>
            <ControlTemplate.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter TargetName="MyBackgroundElement" Property="Background">
                        <Setter.Value>
                            <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                                <GradientStop Color="#FF5BB75B" Offset="0" />
                                <GradientStop Color="#FF398239" Offset="1" />
                            </LinearGradientBrush>
                        </Setter.Value>
                    </Setter>
                    <Setter Property="Cursor" Value="Hand" />
               </Trigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>
    </Setter.Value>
</Setter>
</Style>

在这里，我向x:Name元素添加了Border属性，以便可以使用TargetName上的Setter属性引用它。

Answer 2

从模板

更改此代码段

<Border CornerRadius="2" BorderBrush="#387f38" BorderThickness="1">
   <Border.Background>
       <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
           <GradientStop Color="#FF5BB75B" Offset="0" />
           <GradientStop Color="#FF449B44" Offset="1" />
       </LinearGradientBrush>
   </Border.Background>
   <ContentPresenter x:Name="ButtonContentPresenter" VerticalAlignment="Center" HorizontalAlignment="Center"/>
</Border>

对此（重要的部分是Background="{TemplateBinding Background}"）：

<Border CornerRadius="2" BorderBrush="#387f38" BorderThickness="1" Background="{TemplateBinding Background}">       
   <ContentPresenter x:Name="ButtonContentPresenter" VerticalAlignment="Center" HorizontalAlignment="Center"/>
</Border>

然后在你的风格中添加一个额外的setter：

<Setter Property="Background">
  <Setter.Value>
      <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
          <GradientStop Color="#FF5BB75B" Offset="0" />
          <GradientStop Color="#FF449B44" Offset="1" />
      </LinearGradientBrush>
  </Setter.Value>
</Setter>

WPF按钮样式触发器

2 个答案: