DisplayStateBehavior最初未在列表框项目模板中应用状态转换

问题描述

我有一个包含视觉状态的列表框项目模板。我有将状态设置为开/关状态的DisplayStateBehaviors。我的实现只有1/2可行。在初始显示时，无论DataContext中的值如何，基本状态均处于活动状态。当DataContext中的数据更改时，正确的状态被激活。

I have a listbox item template that contains visual states. I have DisplayStateBehaviors that set the states to either the on/off states. My implementation only 1/2 works. On initial display, the base state is active, regardless of the value in the DataContext. When the data in the DataContext changes, the proper state is activated.

如何在列表框的初始显示中显示正确的状态。

How do I get the proper state displayed on initial display of the listbox.

出于安全原因，我无法复制/粘贴XAML或视图模型代码。

For security reasons I can not copy/paste XAML or View-Model code.

编辑：我无法复制/粘贴真实代码，下面的框架有望重现该问题。

Edit: While I can't copy/paste the real code, the following skeleton hopefully reproduces the problem.

在全局可见的资源文件中：

In a globally visible resource file:

<DataTemplate x:Key="MyObjectItemTemplate">
  <Grid>
    <VisualStateManager.VisualStateGroups>
      ... blend goodness ...
    </VisualStateManager.VisualStateGroups>   
  </Grid>
</DataTemplate>

通过将数据上下文与列表框中的ItemsTemplate属性相关联，将数据上下文传递到数据模板中

The data context is passed into the data template by associating it with the ItemsTemplate attribute of the listbox in the main UI.

<ListBox ... ItemTemplate="{DynamicResource MyObjectItemTemplate}" .../>

推荐答案

我发现了我的问题。如果它对其他人有帮助，我要做的就是将DataTemplate的内容提取到UserControl中。这使一切正常工作。 DataTemplate仍然存在并且仍在使用中，但是它只有一个元素-用户控件。视觉状态都是用户控件的一部分。

I found my issue. In the event it helps others, what I did to fix it was to extract out the guts of the DataTemplate into a UserControl. This made everything work as I expected. The DataTemplate still exists and is still involved, but it only has one element - the user control. The visual states are all part of the user control.

在全局可见的资源文件中：

In a globally visible resource file:

<DataTemplate x:Key="MyObjectItemTemplate">
     <MyNamespace:MyUserControl/>
</DataTemplate>

在单独的文件MyUserControl.cs

In a separated file MyUserControl.cs

<UserControl ... x.Class="MyNamespace.MyUserControl" ...>
  <Grid>
    <VisualStateManager.VisualStateGroups>
      ... blend goodness ...
    </VisualStateManager.VisualStateGroups>   
  </Grid>
</UserControl>

通过将数据上下文与列表框中的ItemsTemplate属性相关联，将数据上下文传递到数据模板中

The data context is passed into the data template by associating it with the ItemsTemplate attribute of the listbox in the main UI.

<ListBox ... ItemTemplate="{DynamicResource MyObjectItemTemplate}" .../>

这篇关于DisplayStateBehavior最初未在列表框项目模板中应用状态转换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！