动画简单的 ContextMenu

问题描述

我有一个按钮，它应该是一个包含多个子项的菜单.菜单应该向下滑动"或类似的东西.我正在尝试使用简单的 TranslateTransform 来完成此操作，但我不断收到以下运行时错误:System.InvalidOperationException:在System.Windows.Controls.ContextMenu"的名称范围内找不到translateTransform"名称.

I have a button, which should a menu with several subitems. The menu should "slide down" or anything like that. I am trying to accomplish this using simple TranslateTransform but I am constantly getting the following runtime error: System.InvalidOperationException: 'translateTransform' name cannot be found in the name scope of 'System.Windows.Controls.ContextMenu'.

是什么原因?有没有办法解决这个问题?是否有菜单动画方法的(免费)替代方法?

What is the cause? Is there a way to fix that? Are there any (free) alternatives to the menu animation approach?

        <Button Name="Settings" Margin="2" Style="{StaticResource GrayGrayButtonStyle}">
            <Image Source="gear.png" />
            <Button.ContextMenu>
                <ContextMenu>
                    <MenuItem Header="Item 0"/>
                    <MenuItem Header="Item 1"/>
                    <MenuItem Header="Item 2"/>
                    <MenuItem Header="Item 3"/>
                    <ContextMenu.RenderTransform>
                        <TranslateTransform x:Name="translateTransform"
                            X="{Binding
                                Path=ActualWidth,
                                RelativeSource={RelativeSource
                                                FindAncestor,
                                                AncestorType={x:Type Button}}}" />
                    </ContextMenu.RenderTransform>
                    <ContextMenu.Triggers>
                        <EventTrigger RoutedEvent="ContextMenu.Loaded">
                            <EventTrigger.Actions>
                                <BeginStoryboard>
                                    <Storyboard>
                                        <DoubleAnimation Storyboard.TargetName="translateTransform"
                                         Storyboard.TargetProperty="(TranslateTransform.X)"
                                         To="0"
                                         BeginTime="0:0:3.5"
                                         AutoReverse="False"
                                         Duration="0:0:2.5" />
                                    </Storyboard>
                                </BeginStoryboard>
                            </EventTrigger.Actions>
                        </EventTrigger>
                    </ContextMenu.Triggers>
                </ContextMenu>
            </Button.ContextMenu>
        </Button>

推荐答案

不知道你要用那个动画来实现什么，但你可以这样写:

Don't know what exactly you're going to achieve with that animation, but you could write it like this:

<DoubleAnimation
    Storyboard.TargetProperty="RenderTransform.(TranslateTransform.X)"
    To="0" ... />

不幸的是，什么都不会被动画化！TranslateTransform.X 属性已经为 0，因为它的绑定会导致错误.但是，您可以像这样编写 TranslateTransform 声明:

Unfortunatly nothing will be animated! The TranslateTransform.X property is already 0, since its binding results in an error. You could however write your TranslateTransform declaration like this:

<TranslateTransform
    X="{Binding Path=PlacementTarget.ActualWidth,
        RelativeSource={RelativeSource AncestorType=ContextMenu}}" />

这篇关于动画简单的 ContextMenu的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！