【发布时间】：2017-02-15 04:20:32
【问题描述】：
我在 Xamarin Forms 项目的App.xaml 中定义了一些样式。但是，如果您将鼠标悬停在按钮上或按下它，这不会影响按钮。此处的字体颜色变为黑色，并且按钮周围出现灰色边框。现在我想覆盖这个样式。
第一次尝试：将定义添加到 UWP 项目的App.xaml
<Application
x:Class="YourApp.UWP.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:YourApp.UWP"
RequestedTheme="Light">
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.ThemeDictionaries>
<ResourceDictionary x:Key="Light">
<SolidColorBrush x:Key="ButtonPointerOverBackgroundThemeBrush" Color="#00FF00" />
</ResourceDictionary>
</ResourceDictionary.ThemeDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
结果：完全没有变化
第二次尝试：覆盖UWP项目App.xaml的PointOver视觉状态
<Application
x:Class="YourApp.UWP.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:YourApp.UWP"
RequestedTheme="Light">
<Application.Resources>
<ResourceDictionary>
<Style TargetType="Button" x:Key="HoverButtonStyle">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="PointerOver">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Border"
Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="#00FF00" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="#00FF00" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
</Application.Resources>
</Application>
结果：完全没有变化，我想我必须应用样式（如果我这样做，按钮似乎不在这里）
第三次尝试：添加完整的按钮样式并应用它
<Style TargetType="Button" x:Key="HoverButtonStyle">
<Setter Property="Background" Value="{ThemeResource ButtonBackgroundThemeBrush}" />
<Setter Property="Foreground" Value="{ThemeResource ButtonForegroundThemeBrush}"/>
<Setter Property="BorderBrush" Value="{ThemeResource ButtonBorderThemeBrush}" />
<Setter Property="BorderThickness" Value="{ThemeResource ButtonBorderThemeThickness}" />
<Setter Property="Padding" Value="12,4,12,4" />
<Setter Property="HorizontalAlignment" Value="Left" />
<Setter Property="VerticalAlignment" Value="Center" />
<Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}" />
<Setter Property="FontWeight" Value="SemiBold" />
<Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal" />
<VisualState x:Name="PointerOver">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Border"
Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource ButtonPointerOverBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonPointerOverForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Border"
Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonPressedBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonPressedForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Border"
Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonDisabledBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Border"
Storyboard.TargetProperty="BorderBrush">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonDisabledBorderThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ButtonDisabledForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="FocusVisualWhite"
Storyboard.TargetProperty="Opacity"
To="1"
Duration="0" />
<DoubleAnimation Storyboard.TargetName="FocusVisualBlack"
Storyboard.TargetProperty="Opacity"
To="1"
Duration="0" />
</Storyboard>
</VisualState>
<VisualState x:Name="Unfocused" />
<VisualState x:Name="PointerFocused" />
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="Border"
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Margin="3">
<ContentPresenter x:Name="ContentPresenter"
Content="{TemplateBinding Content}"
ContentTransitions="{TemplateBinding ContentTransitions}"
ContentTemplate="{TemplateBinding ContentTemplate}"
Margin="{TemplateBinding Padding}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
AutomationProperties.AccessibilityView="Raw"/>
</Border>
<Rectangle x:Name="FocusVisualWhite"
IsHitTestVisible="False"
Stroke="{ThemeResource FocusVisualWhiteStrokeThemeBrush}"
StrokeEndLineCap="Square"
StrokeDashArray="1,1"
Opacity="0"
StrokeDashOffset="1.5" />
<Rectangle x:Name="FocusVisualBlack"
IsHitTestVisible="False"
Stroke="{ThemeResource FocusVisualBlackStrokeThemeBrush}"
StrokeEndLineCap="Square"
StrokeDashArray="1,1"
Opacity="0"
StrokeDashOffset="0.5" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
自定义渲染器：
protected override void OnElementChanged(ElementChangedEventArgs<Button> e)
{
base.OnElementChanged(e);
if (this.Element != null)
{
this.Control.Style = Windows.UI.Xaml.Application.Current.Resources["HoverButtonStyle"] as Windows.UI.Xaml.Style;
}
}
结果：样式似乎已应用，但我在 Xamarin Forms 中定义的背景颜色并没有占据按钮的整个宽度。边框颜色也没有改变。
这是如何正确完成的？
【问题讨论】：
标签： button xamarin xamarin.forms uwp windows-10-universal