当菜单打开时，XAML ResourceDictionary 中的图像在工具栏上消失 [英] Images in XAML ResourceDictionary disappear on ToolBar when Menu opens

问题描述

我已经开始将各种常见的 Image 移动到 ResourceDictionary 中，并注意到我的 WPF 应用程序中有一个奇怪的行为.如果 Image 用于 MenuItem 和 Button 上的 ToolBar，当我打开 Menu 图像消失在 Button 上.

I have started to move various common Images into a ResourceDictionary and noticed an odd behavior in my WPF application. If the Image is used in a MenuItem and in a Button on a ToolBar, when I open the Menu the image disappears on the Button.

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Image x:Key="NewImage"
           Source="/SomeApplication;component/Resources/NewDocumentHS.png"
           Stretch="None"/>
    <!-- ... -->

来自Window的相关XAML:

<Menu>
    <MenuItem Header="_File">
        <MenuItem Header="_New"
                  Command="{Binding NewCommand}"
                  Icon="{DynamicResource NewImage}" />
<!-- ... -->
<ToolBarTray>
    <ToolBar>
        <Button Command="{Binding NewCommand}"
                Content="{DynamicResource NewImage}" />

我认为这是对 ResourceDictionary 中资源的警告，但我无法找到相应的修复方法.StaticResource 和 DynamicResource 都会发生行为.它似乎也不受 ResourceDictionary 独立或与其他人合并的影响.也没有其他资源共享该密钥.

I assume this is a caveat of resources in a ResourceDictionary, but I am unable to discover the appropriate fix for this. Behavior occurs with both StaticResource and DynamicResource. It also doesn't appear to be affected by if the ResourceDictionary stands on its own or if it is merged with others. No other resource shares that key either.

编辑:此外，将 PresentationOptions:Freeze="True" 添加到图像并没有改变这种情况.

Edit: Additionally, adding PresentationOptions:Freeze="True" to the images did not change the situation.

推荐答案

Image 类是一个视觉对象，因此它只能出现在视觉对象树中的一个位置.因此，您不能在多个 MenuItems/Buttons/etc 之间共享它.

The Image class is a visual, so it can only appear in the visual tree in one location. Therefore, you cannot share it among multiple MenuItems/Buttons/etc.

不过，您可以共享 ImageSource(即 Image.Source)值.

You can however share the ImageSource (i.e. Image.Source) value.

在 WPF 中，我相信您可以使用 x:Shared=False"强制 WPF 为每个请求创建一个新实例.

In WPF, I believe you can use x:Shared="False" to force WPF to create a new instance for each request though.

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