先看一下效果吧：

isChecked = false 的时候的效果

isChecked = true 的时候的效果

 然后我们来实现一下这个效果吧

第一步：创建一个空的wpf项目；

第二步：在项目里面添加一个checkbox

    <Grid>
        <CheckBox HorizontalAlignment="Center" IsChecked="True"
                  BorderBrush="Black" VerticalAlignment="Center" 
                  Content="switch" Background="#FF00ADFF"/>
    </Grid>

这个时候的checkbox的样子是这样的

 第三步：在页面中右键checkbox，选择  编辑模板 ，再  编辑副本, 之后确定

 vs就会给我们自动生成一个名为 ”CheckBoxStyle1” 的Checkbox的默认样式的代码,我们通过修改默认样式的代码，把普通的Checkbox变成一个开关。

 第四步：修改默认样式

<Grid x:Name="templateRoot" Background="Transparent" SnapsToDevicePixels="True">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Border x:Name="PART_Border" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" 
BorderThickness="1" Height="14" Width="25" CornerRadius="5">
<Border x:Name="SwitchBorder" BorderThickness="1" BorderBrush="Gray" Background="White" Width="10" 
Margin="1" CornerRadius="5" HorizontalAlignment="Right"/>
</Border>
<ContentPresenter x:Name="contentPresenter" Grid.Column="1" Focusable="False" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" 
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Grid>

把之前的样式代码改成上面的代码，trigger部分，把报错的部分全部删除

这个时候，我们的开关样式就已经完成了

 我们现在需要添加一些trigger和动画来实现切换效果

第五步：添加动画和trigger

<Storyboard x:Key="SwitchChecked">
    <DoubleAnimationUsingKeyFrames Storyboard.TargetName="SwitchBorder" Storyboard.TargetProperty="(FrameworkElement.Width)">
        <EasingDoubleKeyFrame KeyTime="00:00:00" Value="10"/>
        <EasingDoubleKeyFrame KeyTime="00:00:00.2500000" Value="20"/>
        <EasingDoubleKeyFrame KeyTime="00:00:00.5000000" Value="10"/>
    </DoubleAnimationUsingKeyFrames>
    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="SwitchBorder" Storyboard.TargetProperty="(FrameworkElement.HorizontalAlignment)">
        <DiscreteObjectKeyFrame KeyTime="00:00:00" Value="{x:Static HorizontalAlignment.Left}"/>
        <DiscreteObjectKeyFrame KeyTime="00:00:00.2500000" Value="{x:Static HorizontalAlignment.Right}"/>
        <DiscreteObjectKeyFrame KeyTime="00:00:00.5000000" Value="{x:Static HorizontalAlignment.Right}"/>
    </ObjectAnimationUsingKeyFrames>
</Storyboard>


<Storyboard x:Key="SwitchUnchecked">
    <DoubleAnimationUsingKeyFrames Storyboard.TargetName="SwitchBorder" Storyboard.TargetProperty="(FrameworkElement.Width)">
        <EasingDoubleKeyFrame KeyTime="00:00:00" Value="10"/>
        <EasingDoubleKeyFrame KeyTime="00:00:00.2500000" Value="20"/>
        <EasingDoubleKeyFrame KeyTime="00:00:00.5000000" Value="10"/>
    </DoubleAnimationUsingKeyFrames>
    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="SwitchBorder" Storyboard.TargetProperty="(FrameworkElement.HorizontalAlignment)">
        <DiscreteObjectKeyFrame KeyTime="00:00:00" Value="{x:Static HorizontalAlignment.Right}"/>
        <DiscreteObjectKeyFrame KeyTime="00:00:00.2500000" Value="{x:Static HorizontalAlignment.Left}"/>
        <DiscreteObjectKeyFrame KeyTime="00:00:00.5000000" Value="{x:Static HorizontalAlignment.Left}"/>
    </ObjectAnimationUsingKeyFrames>
</Storyboard>

上面这段代码就是表示不同状态下的不同动画效果，通过改变SwitchBoder的宽度和对齐方式，就可以实现了

然后我们再把这段动画效果运用到模板中,再添加3个trigger，就可以了

<ControlTemplate.Triggers>
<Trigger Property="HasContent" Value="true">
<Setter Property="FocusVisualStyle" Value="{StaticResource OptionMarkFocusVisual}"/>
<Setter Property="Padding" Value="4,-1,0,0"/>
</Trigger>
<EventTrigger RoutedEvent="{x:Static CheckBox.CheckedEvent}">
<BeginStoryboard Storyboard="{StaticResource SwitchChecked}"/>
</EventTrigger>
<EventTrigger RoutedEvent="{x:Static CheckBox.UncheckedEvent}">
<BeginStoryboard Storyboard="{StaticResource SwitchUnchecked}"/>
</EventTrigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Background" TargetName="PART_Border" Value="{StaticResource OptionMark.Disabled.Background}"/>
<Setter Property="BorderBrush" TargetName="PART_Border" Value="{StaticResource OptionMark.Disabled.Border}"/>
</Trigger>
<Trigger Property="IsChecked" Value="False">
<Setter Property="Background" Value="White" TargetName="PART_Border"/>
<Setter Property="HorizontalAlignment" Value="Left" TargetName="SwitchBorder"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="BorderBrush" TargetName="PART_Border" Value="{StaticResource OptionMark.MouseOver.Border}"/>
</Trigger>


</ControlTemplate.Triggers>

到现在,样式和动画就已经完成了，我们再把代码全部剪切到App.xaml这个项目资源文件下面，再删掉style的命名,x:Key="CheckBoxStyle1"删掉，

这样子我们的项目里面的checkbox就都是开关的样式了，运行项目也不会报错啦,最后的代码如下

<Application.Resources>


<Storyboard x:Key="SwitchChecked">
<DoubleAnimationUsingKeyFrames Storyboard.TargetName="SwitchBorder" Storyboard.TargetProperty="(FrameworkElement.Width)">
<EasingDoubleKeyFrame KeyTime="00:00:00" Value="10"/>
<EasingDoubleKeyFrame KeyTime="00:00:00.2500000" Value="20"/>
<EasingDoubleKeyFrame KeyTime="00:00:00.5000000" Value="10"/>
</DoubleAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="SwitchBorder" Storyboard.TargetProperty="(FrameworkElement.HorizontalAlignment)">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="{x:Static HorizontalAlignment.Left}"/>
<DiscreteObjectKeyFrame KeyTime="00:00:00.2500000" Value="{x:Static HorizontalAlignment.Right}"/>
<DiscreteObjectKeyFrame KeyTime="00:00:00.5000000" Value="{x:Static HorizontalAlignment.Right}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>


<Storyboard x:Key="SwitchUnchecked">
<DoubleAnimationUsingKeyFrames Storyboard.TargetName="SwitchBorder" Storyboard.TargetProperty="(FrameworkElement.Width)">
<EasingDoubleKeyFrame KeyTime="00:00:00" Value="10"/>
<EasingDoubleKeyFrame KeyTime="00:00:00.2500000" Value="20"/>
<EasingDoubleKeyFrame KeyTime="00:00:00.5000000" Value="10"/>
</DoubleAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="SwitchBorder" Storyboard.TargetProperty="(FrameworkElement.HorizontalAlignment)">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="{x:Static HorizontalAlignment.Right}"/>
<DiscreteObjectKeyFrame KeyTime="00:00:00.2500000" Value="{x:Static HorizontalAlignment.Left}"/>
<DiscreteObjectKeyFrame KeyTime="00:00:00.5000000" Value="{x:Static HorizontalAlignment.Left}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>




<Style x:Key="FocusVisual">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<Rectangle Margin="2" StrokeDashArray="1 2" Stroke="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" SnapsToDevicePixels="true" StrokeThickness="1"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="OptionMarkFocusVisual">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<Rectangle Margin="14,0,0,0" StrokeDashArray="1 2" Stroke="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" SnapsToDevicePixels="true" StrokeThickness="1"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<SolidColorBrush x:Key="OptionMark.Static.Background" Color="#FFFFFFFF"/>
<SolidColorBrush x:Key="OptionMark.Static.Border" Color="#FF707070"/>
<SolidColorBrush x:Key="OptionMark.Static.Glyph" Color="#FF212121"/>
<SolidColorBrush x:Key="OptionMark.MouseOver.Background" Color="#FFF3F9FF"/>
<SolidColorBrush x:Key="OptionMark.MouseOver.Border" Color="#FF5593FF"/>
<SolidColorBrush x:Key="OptionMark.MouseOver.Glyph" Color="#FF212121"/>
<SolidColorBrush x:Key="OptionMark.Pressed.Background" Color="#FFD9ECFF"/>
<SolidColorBrush x:Key="OptionMark.Pressed.Border" Color="#FF3C77DD"/>
<SolidColorBrush x:Key="OptionMark.Pressed.Glyph" Color="#FF212121"/>
<SolidColorBrush x:Key="OptionMark.Disabled.Background" Color="#FFE6E6E6"/>
<SolidColorBrush x:Key="OptionMark.Disabled.Border" Color="#FFBCBCBC"/>
<SolidColorBrush x:Key="OptionMark.Disabled.Glyph" Color="#FF707070"/>
<Style TargetType="{x:Type CheckBox}">
<Setter Property="FocusVisualStyle" Value="{StaticResource FocusVisual}"/>
<Setter Property="Background" Value="{StaticResource OptionMark.Static.Background}"/>
<Setter Property="BorderBrush" Value="{StaticResource OptionMark.Static.Border}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type CheckBox}">
<Grid x:Name="templateRoot" Background="Transparent" SnapsToDevicePixels="True">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Border x:Name="PART_Border" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" 
BorderThickness="1" Height="14" Width="25" CornerRadius="5">
<Border x:Name="SwitchBorder" BorderThickness="1" BorderBrush="Gray" Background="White" Width="10" 
Margin="1" CornerRadius="5" HorizontalAlignment="Right"/>
</Border>
<ContentPresenter x:Name="contentPresenter" Grid.Column="1" Focusable="False" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" 
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="HasContent" Value="true">
<Setter Property="FocusVisualStyle" Value="{StaticResource OptionMarkFocusVisual}"/>
<Setter Property="Padding" Value="4,-1,0,0"/>
</Trigger>
<EventTrigger RoutedEvent="{x:Static CheckBox.CheckedEvent}">
<BeginStoryboard Storyboard="{StaticResource SwitchChecked}"/>
</EventTrigger>
<EventTrigger RoutedEvent="{x:Static CheckBox.UncheckedEvent}">
<BeginStoryboard Storyboard="{StaticResource SwitchUnchecked}"/>
</EventTrigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Background" TargetName="PART_Border" Value="{StaticResource OptionMark.Disabled.Background}"/>
<Setter Property="BorderBrush" TargetName="PART_Border" Value="{StaticResource OptionMark.Disabled.Border}"/>
</Trigger>
<Trigger Property="IsChecked" Value="False">
<Setter Property="Background" Value="White" TargetName="PART_Border"/>
<Setter Property="HorizontalAlignment" Value="Left" TargetName="SwitchBorder"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="BorderBrush" TargetName="PART_Border" Value="{StaticResource OptionMark.MouseOver.Border}"/>
</Trigger>


</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>


</Application.Resources>