禁用按钮时更改按钮的样式 ( IsEnabled=False )

我有一个 UWP 问题。当按钮禁用时（IsEnabled=False），如何更改按钮的样式？

Microsoft added the VisualStateManager (known from Silverlight) to the Windows Universal Plattform. Its purpose is to handle the appearance of a control for different states. The "Disabled" state of a button is a good example. The visual states of a control are defined in its ControlTemplate. To customize these States the easiest way is to right click on your button in the designer and choose "Edit Template" then "Edit a Copy...".

其作用是将控件的默认模板复制到所选位置。 如果控件是按钮，您将拥有如下样式资源：

<Style x:Key="MyButtonStyle" TargetType="Button">
        <Setter Property="Background" Value="{ThemeResource SystemControlBackgroundBaseLowBrush}"/>
        <Setter Property="Foreground" Value="{ThemeResource SystemControlForegroundBaseHighBrush}"/>
        <Setter Property="BorderBrush" Value="{ThemeResource SystemControlForegroundTransparentBrush}"/>
        <Setter Property="BorderThickness" Value="{ThemeResource ButtonBorderThemeThickness}"/>
        <Setter Property="Padding" Value="8,4,8,4"/>
        <Setter Property="HorizontalAlignment" Value="Left"/>
        <Setter Property="VerticalAlignment" Value="Center"/>
        <Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}"/>
        <Setter Property="FontWeight" Value="Normal"/>
        <Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}"/>
        <Setter Property="UseSystemFocusVisuals" Value="True"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Button">
                    <Grid x:Name="RootGrid" Background="{TemplateBinding Background}">
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="CommonStates">
                                <VisualState x:Name="Normal"/>
                                <VisualState x:Name="PointerOver">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseMediumLowBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseHighBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Pressed">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="RootGrid">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlBackgroundBaseMediumLowBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightTransparentBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseHighBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <PointerDownThemeAnimation Storyboard.TargetName="RootGrid"/>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Disabled">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="RootGrid">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlBackgroundBaseLowBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledBaseLowBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledTransparentBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <ContentPresenter x:Name="ContentPresenter" AutomationProperties.AccessibilityView="Raw" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" ContentTemplate="{TemplateBinding ContentTemplate}" ContentTransitions="{TemplateBinding ContentTransitions}" Content="{TemplateBinding Content}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

现在您可以看到按钮的视觉状态以及与其关联的设置器/动画。您可以手动修改它们，也可以打开 Microsoft Blend 2015。它具有设计视觉状态的强大功能。右键单击按钮，然后单击 Blend 中的“编辑模板”->“编辑当前”，您可以在状态选项卡（左侧）上看到控件的所有状态。

当您选择“禁用”状态时，您将看到设计器窗口周围有一个红色边框。左上角的文字告诉您“禁用状态录制已开启...”。这意味着对控件树中对象的每次更改都会使控件处于“禁用”状态。例如，您可以将 Contentpresenter 的前景色更改为禁用状态。以下动画将添加到您的 XAML 中：

                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <SolidColorBrush Color="#FF225EFF"/>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>

有关 VisualStateManager 以及从哪里开始的更多信息，请查看Visual Studio 2015 中的新 XAML 工具和 Channel9 上的混合视频.

希望这有帮助