panel 怎么隐藏子控件

panel 如何隐藏子控件
wpf刚学，碰到一个问题

                            <DockPanel>
                                <CheckBox />
                                <Image Width="16" Height="16"></Image>
                                <TextBlock Text="名称"></TextBlock>
                                <Button Content="修改名称" />
                                <Button Content="添加附件" />
                                <Button Content="历史"/>
                                <Button Content="备份"/>
                                <Button Content="更多"/>
                            </DockPanel>

当鼠标在DockPanel上时，Button可见。
当鼠标离开DockPanel时，Button隐藏。
如何用xaml写
------解决方案--------------------

 <StackPanel>

            <DockPanel Width="300" Height="50">

                <DockPanel.Triggers>

                    <EventTrigger RoutedEvent="Mouse.MouseEnter">

                        <BeginStoryboard>

                            <Storyboard>

                                <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)"

                                                               Storyboard.TargetName="myWrapPanel">

                                    <DiscreteObjectKeyFrame KeyTime="0:0:0.01" Value="{x:Static Visibility.Visible}"></DiscreteObjectKeyFrame>

                                </ObjectAnimationUsingKeyFrames>

                            </Storyboard>

                        </BeginStoryboard>

                    </EventTrigger>

                    <EventTrigger RoutedEvent="Mouse.MouseLeave">

                        <BeginStoryboard>

                            <Storyboard>

                                <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)"

                                                               Storyboard.TargetName="myWrapPanel">