求助：wpf编译后出现错误
代码如下：<Application x:Class="BindingStudent.App"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="SystemWindow.xaml">
<Application.Resources>
<Style x:Key="TabItemButtonStyle" TargetType="{x:Type Button}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver">
<Storyboard>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="ellipse">
<EasingDoubleKeyFrame KeyTime="0" Value="1"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleX)" Storyboard.TargetName="ellipse">
<EasingDoubleKeyFrame KeyTime="0" Value="1.222"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.X)" Storyboard.TargetName="ellipse">
<EasingDoubleKeyFrame KeyTime="0" Value="-2"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleY)" Storyboard.TargetName="ellipse">
<EasingDoubleKeyFrame KeyTime="0" Value="1.176"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.Y)" Storyboard.TargetName="ellipse">
<EasingDoubleKeyFrame KeyTime="0" Value="-1.5"/>
</DoubleAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" Storyboard.TargetName="ellipse">
<EasingColorKeyFrame KeyTime="0" Value="#FF1D96D6"/>
</ColorAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="path">
<EasingDoubleKeyFrame KeyTime="0" Value="1"/>
</DoubleAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames Storyboard.TargetProperty="(Shape.Stroke).(SolidColorBrush.Color)" Storyboard.TargetName="path">
<EasingColorKeyFrame KeyTime="0" Value="#FFF30909"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed"/>
<VisualState x:Name="Disabled"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Path Data="M0.5,0.5 L13.750018,13.999998 M13.750017,0.5 L0.74998773,14.000002" Stretch="Fill" StrokeThickness="3" Stroke="Blue"/>
<ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
<Ellipse x:Name="ellipse" Margin="-0.333,0,-3.417,-2.5" Opacity="0" RenderTransformOrigin="0.5,0.5" Fill="Black">
<Ellipse.RenderTransform>
<TransformGroup>
<ScaleTransform/>
<SkewTransform/>
<RotateTransform/>
<TranslateTransform/>
</TransformGroup>
</Ellipse.RenderTransform>
</Ellipse>
<Path x:Name="path" Data="M14.166667,1.5 L0.83300014,14.499667 M0.5,0.5 L13.833333,14.166333" Margin="-0.833,-0.833,0.416,0.333" Opacity="0" Stretch="Fill" Stroke="Black"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsFocused" Value="True"/>
<Trigger Property="IsDefaulted" Value="True"/>
<Trigger Property="IsMouseOver" Value="True"/>
<Trigger Property="IsPressed" Value="True"/>
<Trigger Property="IsEnabled" Value="False"/>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
编译后错误：错误 类型引用不明确。至少有两个名称空间(“System.Windows”和“System.Windows”)中已出现名为“VisualState”的类型。请考虑调整程序集 XmlnsDefinition 特性。
不知怎么解决，我没有引用什么命名空间的呀 --------------------编程问答-------------------- 我复制你的代码编译，OK的
1>------ Build started: Project: WpfApplication1, Configuration: Debug Any CPU ------
1> WpfApplication1 -> C:\Users\nonocast\Desktop\JsonNETSolution\WpfApplication1\bin\Debug\WpfApplication1.exe
========== Build: 1 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========
补充：.NET技术 , C#
