动画按钮从一个点到另一个点答案

【问题标题】：Animate button from one point to another动画按钮从一个点到另一个点
【发布时间】：2019-05-10 03:08:38
【问题描述】：

我有一个包含一些元素和一个按钮的扩展器。当展开器折叠时，我想在展开器的标题中显示按钮以便于访问。当展开器展开时，我希望按钮成为展开器内容的一部分。

当展开器展开和折叠时，我可以让标题中的按钮淡入和淡出，但我想更进一步。我希望扩展器内容中的按钮在折叠时向上移动到标题中的位置，并在展开时向下移动到内容的位置。

我可以通过使用混合并在两个按钮之间画一条线并将其转换为运动路径来获得一些接近。但是，使用这种方法很难获得准确的定位。我的一部分觉得画出路径有点过于复杂。我想要的只是让按钮 A 变成按钮 B。

目前我只关心按钮的位置。这两个按钮的大小不同，但为按钮的宽度和高度设置动画更直接:)

这是我快速制作的一个示例程序，用于演示我正在使用的内容。它主要只是为了提供一个视觉布局。本例中不包含淡入淡出动画和路径动画。


<Window x:Class="test.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:test"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">

    <Window.Resources>
        <Style TargetType="{x:Type Button}">
            <Setter Property="Margin" Value="5" />
            <Setter Property="Background" Value="Red" />
            <Setter Property="Foreground" Value="White" />
        </Style>
    </Window.Resources>

    <Grid>
        <Expander Margin="5" BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Stretch" IsExpanded="True">
            <Expander.Header>
                <DockPanel Margin="5">
                    <TextBlock Margin="5" VerticalAlignment="Center">Hello World</TextBlock>
                    <Button Padding="5">Button</Button>
                </DockPanel>

            </Expander.Header>
            <Expander.Content>
                <StackPanel Orientation="Horizontal">
                    <Canvas Margin="5" Width="300" Background="Black" />

                    <StackPanel>
                        <StackPanel.Resources>
                            <Style TargetType="{x:Type RadioButton}">
                                <Setter Property="Margin" Value="5" />
                            </Style>
                        </StackPanel.Resources>
                        <RadioButton IsChecked="True">Option 1</RadioButton>
                        <RadioButton>Option 2</RadioButton>
                        <RadioButton>Option 3</RadioButton>
                        <RadioButton>Option 4</RadioButton>

                        <Button Width="100" Height="50">Button</Button>
                    </StackPanel>
                </StackPanel>
            </Expander.Content>
        </Expander>
    </Grid>
</Window>

非常感谢任何帮助。我试图找到一些资源来提供帮助，但我所能找到的只是沿着路径移动元素，而不是移动到特定点，除非我遗漏了一些明显的东西。

谢谢

【问题讨论】：

标签： c# wpf blend wpf-animation

【解决方案1】：

这不是一件小事。

基本上，您试图在可视化树的两个完全不同部分之间为按钮设置动画，因此您必须将整个内容模板化并将所有内容包装在包含扩展器和按钮的父布局中您正在尝试制作动画。

模板化你的扩展器应该不会太难，只需将光标移动到它的 XAML，转到属性选项卡，选择“模板”并单击右侧的小方块即可生成新 ControlTemplate 的所有代码。我已经在下面的代码中为您完成了，但主题可能全都错了，所以您需要自己做。

下一步是创建两个矩形，一个在扩展器标题中，一个在其内容区域中。将它们的大小设置为您希望按钮的大小，但将填充设置为透明；它们只是帮助布局的占位符，稍后您将使用它们来对齐按钮控件。

现在您需要返回到您的 ControlTemplate 并将所有内容（即顶级边框）包装在一个网格中。您还需要将实际按钮放置为此网格的子级。

最后，您需要一个绑定到您创建的两个矩形的行为（以便它可以计算 From 和 To 点）、父网格（以便它有一个父控件，它可以为您的按钮设置动画）和扩展器（因此它可以触发动画以响应扩展器的展开和折叠）。实际的动画本身可以是为按钮的 Margin 设置动画的 ThicknessAnimation。

把所有这些放在一起，你就得到了：

 xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
 xmlns:behaviors="clr-namespace:WpfApp1.Behaviors"


<UserControl.Resources>
    <ControlTemplate x:Key="ExpanderControlTemplate1" TargetType="{x:Type Expander}">
        <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" CornerRadius="3" SnapsToDevicePixels="True">
            <Grid x:Name="Grid">
                <DockPanel>
                    <ToggleButton x:Name="HeaderSite" ContentTemplate="{TemplateBinding HeaderTemplate}" Content="{TemplateBinding Header}" DockPanel.Dock="Top" Foreground="{TemplateBinding Foreground}" FontWeight="{TemplateBinding FontWeight}" FontStyle="{TemplateBinding FontStyle}" FontStretch="{TemplateBinding FontStretch}" FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" IsChecked="{Binding IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Margin="1" MinWidth="0" MinHeight="0" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}">
                        <ToggleButton.FocusVisualStyle>
                            <Style>
                                <Setter Property="Control.Template">
                                    <Setter.Value>
                                        <ControlTemplate>
                                            <Border>
                                                <Rectangle Margin="0" SnapsToDevicePixels="True" Stroke="Black" StrokeThickness="1" StrokeDashArray="1 2"/>
                                            </Border>
                                        </ControlTemplate>
                                    </Setter.Value>
                                </Setter>
                            </Style>
                        </ToggleButton.FocusVisualStyle>
                        <ToggleButton.Style>
                            <Style TargetType="{x:Type ToggleButton}">
                                <Setter Property="Template">
                                    <Setter.Value>
                                        <ControlTemplate TargetType="{x:Type ToggleButton}">
                                            <Border Padding="{TemplateBinding Padding}">
                                                <Grid Background="Transparent" SnapsToDevicePixels="False">
                                                    <Grid.ColumnDefinitions>
                                                        <ColumnDefinition Width="19"/>
                                                        <ColumnDefinition Width="*"/>
                                                    </Grid.ColumnDefinitions>
                                                    <Ellipse x:Name="circle" Fill="White" HorizontalAlignment="Center" Height="19" Stroke="#FF333333" VerticalAlignment="Center" Width="19"/>
                                                    <Path x:Name="arrow" Data="M1,1.5L4.5,5 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="False" Stroke="#FF333333" StrokeThickness="2" VerticalAlignment="Center"/>
                                                    <ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Grid.Column="1" ContentStringFormat="{TemplateBinding ContentStringFormat}" HorizontalAlignment="Left" Margin="4,0,0,0" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Center"/>
                                                </Grid>
                                            </Border>
                                            <ControlTemplate.Triggers>
                                                <Trigger Property="IsChecked" Value="True">
                                                    <Setter Property="Data" TargetName="arrow" Value="M1,4.5L4.5,1 8,4.5"/>
                                                </Trigger>
                                                <Trigger Property="IsMouseOver" Value="True">
                                                    <Setter Property="Stroke" TargetName="circle" Value="#FF5593FF"/>
                                                    <Setter Property="Fill" TargetName="circle" Value="#FFF3F9FF"/>
                                                    <Setter Property="Stroke" TargetName="arrow" Value="Black"/>
                                                </Trigger>
                                                <Trigger Property="IsPressed" Value="True">
                                                    <Setter Property="Stroke" TargetName="circle" Value="#FF3C77DD"/>
                                                    <Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
                                                    <Setter Property="Fill" TargetName="circle" Value="#FFD9ECFF"/>
                                                    <Setter Property="Stroke" TargetName="arrow" Value="Black"/>
                                                </Trigger>
                                                <Trigger Property="IsEnabled" Value="False">
                                                    <Setter Property="Stroke" TargetName="circle" Value="#FFBCBCBC"/>
                                                    <Setter Property="Fill" TargetName="circle" Value="#FFE6E6E6"/>
                                                    <Setter Property="Stroke" TargetName="arrow" Value="#FF707070"/>
                                                </Trigger>
                                            </ControlTemplate.Triggers>
                                        </ControlTemplate>
                                    </Setter.Value>
                                </Setter>
                            </Style>
                        </ToggleButton.Style>
                    </ToggleButton>
                    <ContentPresenter x:Name="ExpandSite" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" ContentStringFormat="{TemplateBinding ContentStringFormat}" DockPanel.Dock="Bottom" Focusable="False" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" Visibility="Collapsed" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                </DockPanel>
                <Button Width="100" Height="50" Content="Button" HorizontalAlignment="Left" VerticalAlignment="Top">
                    <i:Interaction.Behaviors>
                        <behaviors:AnimatedMarginBehavior ElementA="{Binding ElementName=ElementA}" ElementB="{Binding ElementName=ElementB}" Grid="{Binding ElementName=Grid}" Parent="{Binding RelativeSource={RelativeSource AncestorType=Expander}}" />
                    </i:Interaction.Behaviors>
                </Button>
            </Grid>
        </Border>
        <ControlTemplate.Triggers>
            <Trigger Property="IsExpanded" Value="True">
                <Setter Property="Visibility" TargetName="ExpandSite" Value="Visible"/>
            </Trigger>
            <Trigger Property="ExpandDirection" Value="Right">
                <Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Right"/>
                <Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Left"/>
                <Setter Property="Style" TargetName="HeaderSite">
                    <Setter.Value>
                        <Style TargetType="{x:Type ToggleButton}">
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate TargetType="{x:Type ToggleButton}">
                                        <Border Padding="{TemplateBinding Padding}">
                                            <Grid Background="Transparent" SnapsToDevicePixels="False">
                                                <Grid.RowDefinitions>
                                                    <RowDefinition Height="19"/>
                                                    <RowDefinition Height="*"/>
                                                </Grid.RowDefinitions>
                                                <Grid>
                                                    <Grid.LayoutTransform>
                                                        <TransformGroup>
                                                            <RotateTransform Angle="-90"/>
                                                        </TransformGroup>
                                                    </Grid.LayoutTransform>
                                                    <Ellipse x:Name="circle" Fill="White" HorizontalAlignment="Center" Height="19" Stroke="#FF333333" VerticalAlignment="Center" Width="19"/>
                                                    <Path x:Name="arrow" Data="M1,1.5L4.5,5 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="False" Stroke="#FF333333" StrokeThickness="2" VerticalAlignment="Center"/>
                                                </Grid>
                                                <ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" ContentStringFormat="{TemplateBinding ContentStringFormat}" HorizontalAlignment="Center" Margin="0,4,0,0" Grid.Row="1" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Top"/>
                                            </Grid>
                                        </Border>
                                        <ControlTemplate.Triggers>
                                            <Trigger Property="IsChecked" Value="True">
                                                <Setter Property="Data" TargetName="arrow" Value="M1,4.5L4.5,1 8,4.5"/>
                                            </Trigger>
                                            <Trigger Property="IsMouseOver" Value="True">
                                                <Setter Property="Stroke" TargetName="circle" Value="#FF5593FF"/>
                                                <Setter Property="Fill" TargetName="circle" Value="#FFF3F9FF"/>
                                                <Setter Property="Stroke" TargetName="arrow" Value="Black"/>
                                            </Trigger>
                                            <Trigger Property="IsPressed" Value="True">
                                                <Setter Property="Stroke" TargetName="circle" Value="#FF3C77DD"/>
                                                <Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
                                                <Setter Property="Fill" TargetName="circle" Value="#FFD9ECFF"/>
                                                <Setter Property="Stroke" TargetName="arrow" Value="Black"/>
                                            </Trigger>
                                            <Trigger Property="IsEnabled" Value="False">
                                                <Setter Property="Stroke" TargetName="circle" Value="#FFBCBCBC"/>
                                                <Setter Property="Fill" TargetName="circle" Value="#FFE6E6E6"/>
                                                <Setter Property="Stroke" TargetName="arrow" Value="#FF707070"/>
                                            </Trigger>
                                        </ControlTemplate.Triggers>
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </Setter.Value>
                </Setter>
            </Trigger>
            <Trigger Property="ExpandDirection" Value="Up">
                <Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Top"/>
                <Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Bottom"/>
                <Setter Property="Style" TargetName="HeaderSite">
                    <Setter.Value>
                        <Style TargetType="{x:Type ToggleButton}">
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate TargetType="{x:Type ToggleButton}">
                                        <Border Padding="{TemplateBinding Padding}">
                                            <Grid Background="Transparent" SnapsToDevicePixels="False">
                                                <Grid.ColumnDefinitions>
                                                    <ColumnDefinition Width="19"/>
                                                    <ColumnDefinition Width="*"/>
                                                </Grid.ColumnDefinitions>
                                                <Grid>
                                                    <Grid.LayoutTransform>
                                                        <TransformGroup>
                                                            <RotateTransform Angle="180"/>
                                                        </TransformGroup>
                                                    </Grid.LayoutTransform>
                                                    <Ellipse x:Name="circle" Fill="White" HorizontalAlignment="Center" Height="19" Stroke="#FF333333" VerticalAlignment="Center" Width="19"/>
                                                    <Path x:Name="arrow" Data="M1,1.5L4.5,5 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="False" Stroke="#FF333333" StrokeThickness="2" VerticalAlignment="Center"/>
                                                </Grid>
                                                <ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Grid.Column="1" ContentStringFormat="{TemplateBinding ContentStringFormat}" HorizontalAlignment="Left" Margin="4,0,0,0" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Center"/>
                                            </Grid>
                                        </Border>
                                        <ControlTemplate.Triggers>
                                            <Trigger Property="IsChecked" Value="True">
                                                <Setter Property="Data" TargetName="arrow" Value="M1,4.5L4.5,1 8,4.5"/>
                                            </Trigger>
                                            <Trigger Property="IsMouseOver" Value="True">
                                                <Setter Property="Stroke" TargetName="circle" Value="#FF5593FF"/>
                                                <Setter Property="Fill" TargetName="circle" Value="#FFF3F9FF"/>
                                                <Setter Property="Stroke" TargetName="arrow" Value="Black"/>
                                            </Trigger>
                                            <Trigger Property="IsPressed" Value="True">
                                                <Setter Property="Stroke" TargetName="circle" Value="#FF3C77DD"/>
                                                <Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
                                                <Setter Property="Fill" TargetName="circle" Value="#FFD9ECFF"/>
                                                <Setter Property="Stroke" TargetName="arrow" Value="Black"/>
                                            </Trigger>
                                            <Trigger Property="IsEnabled" Value="False">
                                                <Setter Property="Stroke" TargetName="circle" Value="#FFBCBCBC"/>
                                                <Setter Property="Fill" TargetName="circle" Value="#FFE6E6E6"/>
                                                <Setter Property="Stroke" TargetName="arrow" Value="#FF707070"/>
                                            </Trigger>
                                        </ControlTemplate.Triggers>
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </Setter.Value>
                </Setter>
            </Trigger>
            <Trigger Property="ExpandDirection" Value="Left">
                <Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Left"/>
                <Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Right"/>
                <Setter Property="Style" TargetName="HeaderSite">
                    <Setter.Value>
                        <Style TargetType="{x:Type ToggleButton}">
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate TargetType="{x:Type ToggleButton}">
                                        <Border Padding="{TemplateBinding Padding}">
                                            <Grid Background="Transparent" SnapsToDevicePixels="False">
                                                <Grid.RowDefinitions>
                                                    <RowDefinition Height="19"/>
                                                    <RowDefinition Height="*"/>
                                                </Grid.RowDefinitions>
                                                <Grid>
                                                    <Grid.LayoutTransform>
                                                        <TransformGroup>
                                                            <RotateTransform Angle="90"/>
                                                        </TransformGroup>
                                                    </Grid.LayoutTransform>
                                                    <Ellipse x:Name="circle" Fill="White" HorizontalAlignment="Center" Height="19" Stroke="#FF333333" VerticalAlignment="Center" Width="19"/>
                                                    <Path x:Name="arrow" Data="M1,1.5L4.5,5 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="False" Stroke="#FF333333" StrokeThickness="2" VerticalAlignment="Center"/>
                                                </Grid>
                                                <ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" ContentStringFormat="{TemplateBinding ContentStringFormat}" HorizontalAlignment="Center" Margin="0,4,0,0" Grid.Row="1" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Top"/>
                                            </Grid>
                                        </Border>
                                        <ControlTemplate.Triggers>
                                            <Trigger Property="IsChecked" Value="True">
                                                <Setter Property="Data" TargetName="arrow" Value="M1,4.5L4.5,1 8,4.5"/>
                                            </Trigger>
                                            <Trigger Property="IsMouseOver" Value="True">
                                                <Setter Property="Stroke" TargetName="circle" Value="#FF5593FF"/>
                                                <Setter Property="Fill" TargetName="circle" Value="#FFF3F9FF"/>
                                                <Setter Property="Stroke" TargetName="arrow" Value="Black"/>
                                            </Trigger>
                                            <Trigger Property="IsPressed" Value="True">
                                                <Setter Property="Stroke" TargetName="circle" Value="#FF3C77DD"/>
                                                <Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
                                                <Setter Property="Fill" TargetName="circle" Value="#FFD9ECFF"/>
                                                <Setter Property="Stroke" TargetName="arrow" Value="Black"/>
                                            </Trigger>
                                            <Trigger Property="IsEnabled" Value="False">
                                                <Setter Property="Stroke" TargetName="circle" Value="#FFBCBCBC"/>
                                                <Setter Property="Fill" TargetName="circle" Value="#FFE6E6E6"/>
                                                <Setter Property="Stroke" TargetName="arrow" Value="#FF707070"/>
                                            </Trigger>
                                        </ControlTemplate.Triggers>
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </Setter.Value>
                </Setter>
            </Trigger>
            <Trigger Property="IsEnabled" Value="False">
                <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
            </Trigger>
        </ControlTemplate.Triggers>
    </ControlTemplate>
</UserControl.Resources>

<Grid>
    <Expander Margin="5" BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Stretch" IsExpanded="True" Template="{DynamicResource ExpanderControlTemplate1}">
        <Expander.Header>
            <DockPanel Margin="5">
                <TextBlock Margin="5" VerticalAlignment="Center">Hello World</TextBlock>
                <Rectangle x:Name="ElementA" Width="100" Height="50" Fill="Transparent" />
            </DockPanel>
        </Expander.Header>
        <Expander.Content>
            <StackPanel Orientation="Horizontal">
                <Canvas Margin="5" Width="300" Background="Black" />

                <StackPanel>
                    <StackPanel.Resources>
                        <Style TargetType="{x:Type RadioButton}">
                            <Setter Property="Margin" Value="5" />
                        </Style>
                    </StackPanel.Resources>
                    <RadioButton IsChecked="True">Option 1</RadioButton>
                    <RadioButton>Option 2</RadioButton>
                    <RadioButton>Option 3</RadioButton>
                    <RadioButton>Option 4</RadioButton>
                    <Rectangle x:Name="ElementB" Width="100" Height="50" Fill="Transparent" />
                </StackPanel>
            </StackPanel>
        </Expander.Content>
    </Expander>
</Grid>

以及行为：

public class AnimatedMarginBehavior : Behavior<FrameworkElement>
{
    private ThicknessAnimation Animation = new ThicknessAnimation();

    public FrameworkElement ElementA
    {
        get { return GetValue(ElementAProperty) as FrameworkElement; }
        set { SetValue(ElementAProperty, value); }
    }

    public static readonly DependencyProperty ElementAProperty =
        DependencyProperty.Register("ElementA", typeof(FrameworkElement), typeof(AnimatedMarginBehavior),
            new PropertyMetadata(default(FrameworkElement), (d, e) => (d as AnimatedMarginBehavior).OnBindingChanged(e)));

    public FrameworkElement ElementB
    {
        get { return GetValue(ElementBProperty) as FrameworkElement; }
        set { SetValue(ElementBProperty, value); }
    }

    public static readonly DependencyProperty ElementBProperty =
        DependencyProperty.Register("ElementB", typeof(FrameworkElement), typeof(AnimatedMarginBehavior),
            new PropertyMetadata(default(FrameworkElement), (d, e) => (d as AnimatedMarginBehavior).OnBindingChanged(e)));

    public Expander Parent
    {
        get { return GetValue(ParentProperty) as Expander; }
        set { SetValue(ParentProperty, value); }
    }

    public static readonly DependencyProperty ParentProperty =
        DependencyProperty.Register("Parent", typeof(Expander), typeof(AnimatedMarginBehavior),
            new PropertyMetadata(default(Expander), (d, e) => (d as AnimatedMarginBehavior).OnBindingChanged(e)));

    public Grid Grid
    {
        get { return GetValue(GridProperty) as Grid; }
        set { SetValue(GridProperty, value); }
    }

    public static readonly DependencyProperty GridProperty =
        DependencyProperty.Register("Grid", typeof(Grid), typeof(AnimatedMarginBehavior),
            new PropertyMetadata(default(Grid), (d, e) => (d as AnimatedMarginBehavior).OnBindingChanged(e)));

    private void OnBindingChanged(DependencyPropertyChangedEventArgs e)
    {
        if (this.ElementA == null)
            return;
        if (this.ElementB == null)
            return;
        if (this.Parent == null)
            return;
        if (this.Grid == null)
            return;

        // set initial position based on whether or not the control is expanded
        var currentElement = this.Parent.IsExpanded ? this.ElementB : this.ElementA;
        UIElement container = VisualTreeHelper.GetParent(this.Grid) as UIElement;
        var pos = currentElement.TranslatePoint(new Point(0, 0), container);
        this.AssociatedObject.SetValue(FrameworkElement.MarginProperty, new Thickness(pos.X-1, pos.Y-1, 0, 0));

        // get notification when the expander changes state
        this.Parent.Collapsed += (_s1, _e1) =>
        {
            container = VisualTreeHelper.GetParent(this.Grid) as UIElement;
            var from = this.ElementB.TranslatePoint(new Point(0, 0), container);
            var to = this.ElementA.TranslatePoint(new Point(0, 0), container);
            this.Animation.From = new Thickness(from.X, from.Y, 0, 0);
            this.Animation.To = new Thickness(to.X, to.Y, 0, 0);
            this.Animation.Duration = TimeSpan.FromMilliseconds(500);
            this.Animation.EasingFunction = new QuadraticEase { EasingMode = EasingMode.EaseInOut };
            this.AssociatedObject.BeginAnimation(FrameworkElement.MarginProperty, this.Animation);
        };

        this.Parent.Expanded += (_s2, _e2) =>
        {
            container = VisualTreeHelper.GetParent(this.Grid) as UIElement;
            var from = this.ElementA.TranslatePoint(new Point(0, 0), container);
            var to = this.ElementB.TranslatePoint(new Point(0, 0), container);
            this.Animation.From = new Thickness(from.X, from.Y, 0, 0);
            this.Animation.To = new Thickness(to.X, to.Y, 0, 0);
            this.Animation.Duration = TimeSpan.FromMilliseconds(500);
            this.Animation.EasingFunction = new QuadraticEase { EasingMode = EasingMode.EaseInOut };
            this.AssociatedObject.BeginAnimation(FrameworkElement.MarginProperty, this.Animation);
        };
    }
}

这是一个非常粗略且现成的示例，它提供了如何执行此操作的一般概念，您肯定会想要详细了解它并稍微清理一下。

结果：

【讨论】：

【解决方案2】：

只用 xaml 直接尝试，没有任何 c# 代码。希望这对你有用。

  <Window.Resources>
        <Style TargetType="{x:Type Button}">
            <Setter Property="Margin" Value="5" />
            <Setter Property="Background" Value="Red" />
            <Setter Property="Foreground" Value="White" />
        </Style>
        <Storyboard x:Key="Storyboard1">
            <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.X)" Storyboard.TargetName="button">
                <EasingDoubleKeyFrame KeyTime="0:0:0.1" Value="221"/>
            </DoubleAnimationUsingKeyFrames>
            <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.Y)" Storyboard.TargetName="button">
                <EasingDoubleKeyFrame KeyTime="0:0:0.0001" Value="161"/>
            </DoubleAnimationUsingKeyFrames>
        </Storyboard>
        <Storyboard x:Key="Storyboard2">
            <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.X)" Storyboard.TargetName="button">
                <EasingDoubleKeyFrame KeyTime="0" Value="221">
                    <EasingDoubleKeyFrame.EasingFunction>
                        <ElasticEase EasingMode="EaseInOut" Oscillations="0" Springiness="0"/>
                    </EasingDoubleKeyFrame.EasingFunction>
                </EasingDoubleKeyFrame>
                <EasingDoubleKeyFrame KeyTime="0" Value="161">
                    <EasingDoubleKeyFrame.EasingFunction>
                        <ElasticEase EasingMode="EaseInOut" Oscillations="0" Springiness="0"/>
                    </EasingDoubleKeyFrame.EasingFunction>
                </EasingDoubleKeyFrame>
                <EasingDoubleKeyFrame KeyTime="0:0:0.1" Value="-3">
                    <EasingDoubleKeyFrame.EasingFunction>
                        <ElasticEase EasingMode="EaseInOut" Oscillations="0" Springiness="0"/>
                    </EasingDoubleKeyFrame.EasingFunction>
                </EasingDoubleKeyFrame>
                <!-- <EasingDoubleKeyFrame KeyTime="0:0:0.1" Value="0"/> -->
            </DoubleAnimationUsingKeyFrames>
            <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.Y)" Storyboard.TargetName="button">
                <EasingDoubleKeyFrame KeyTime="0" Value="156">
                    <EasingDoubleKeyFrame.EasingFunction>
                        <ElasticEase EasingMode="EaseInOut" Oscillations="0" Springiness="0"/>
                    </EasingDoubleKeyFrame.EasingFunction>
                </EasingDoubleKeyFrame>
                <EasingDoubleKeyFrame KeyTime="0:0:0.1" Value="-1">
                    <EasingDoubleKeyFrame.EasingFunction>
                        <ElasticEase EasingMode="EaseInOut" Oscillations="0" Springiness="0"/>
                    </EasingDoubleKeyFrame.EasingFunction>
                </EasingDoubleKeyFrame>
            </DoubleAnimationUsingKeyFrames>
        </Storyboard>
    </Window.Resources>
    <Window.Triggers>
        <EventTrigger RoutedEvent="FrameworkElement.Loaded" SourceName="window">
            <StopStoryboard x:Name="Storyboard1_Storyboard" BeginStoryboardName="Storyboard1_Storyboard"/>
            <BeginStoryboard x:Name="Storyboard1_BeginStoryboard" Storyboard="{StaticResource Storyboard1}"/>
        </EventTrigger>
        <EventTrigger RoutedEvent="Expander.Expanded" SourceName="expander">
            <BeginStoryboard Storyboard="{StaticResource Storyboard1}"/>
        </EventTrigger>
        <EventTrigger RoutedEvent="Expander.Collapsed" SourceName="expander">
            <BeginStoryboard Storyboard="{StaticResource Storyboard2}"/>
        </EventTrigger>
    </Window.Triggers>

    <Grid>
        <Expander x:Name="expander" Margin="5" BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Stretch" IsExpanded="False">
            <Expander.Header>
                <StackPanel Width="195.313">
                    <Grid x:Name="grid" RenderTransformOrigin="0.5,0.5">
                        <Grid.RenderTransform>
                            <TransformGroup>
                                <ScaleTransform/>
                                <SkewTransform/>
                                <RotateTransform/>
                                <TranslateTransform/>
                            </TransformGroup>
                        </Grid.RenderTransform>
                        <TextBlock x:Name="textBlock" Margin="5" VerticalAlignment="Center" RenderTransformOrigin="0.5,0.5">
                            <TextBlock.RenderTransform>
                                <TransformGroup>
                                    <ScaleTransform/>
                                    <SkewTransform/>
                                    <RotateTransform/>
                                    <TranslateTransform/>
                                </TransformGroup>
                            </TextBlock.RenderTransform><Run Text="Hello World"/></TextBlock>
                        <Button x:Name="button" Padding="5" RenderTransformOrigin="0.5,0.5" Content="Button" Margin="93,5,5,5">
                            <Button.RenderTransform>
                                <TransformGroup>
                                    <ScaleTransform/>
                                    <SkewTransform/>
                                    <RotateTransform/>
                                    <TranslateTransform/>
                                </TransformGroup>
                            </Button.RenderTransform>
                        </Button>
                    </Grid>
                </StackPanel>


            </Expander.Header>
            <StackPanel Orientation="Horizontal">
                <Canvas Margin="5" Width="300" Background="Black" />

                <StackPanel>
                    <StackPanel.Resources>
                        <Style TargetType="{x:Type RadioButton}">
                            <Setter Property="Margin" Value="5" />
                        </Style>
                    </StackPanel.Resources>
                    <RadioButton IsChecked="True" Content="Option 1"/>
                    <RadioButton Content="Option 2"/>
                    <RadioButton Content="Option 3"/>
                    <RadioButton Content="Option 4"/>
                </StackPanel>
            </StackPanel>
        </Expander>
    </Grid>

小心设计。

【讨论】：

有趣的解决方案。唯一的问题是它对按钮的位置进行了硬编码，因此一旦您对布局进行任何更改（例如更改字体大小、启用 Windows 可访问性选项、将文本切换为其他语言等），它就会中断.看看这个方法是否可以在仍然让布局管理器做它的事情的同时使用会很有趣。
我同意你的看法。如果不是复杂的设计，那么这段代码很好。