我如何知道更改时何时加载ContentControl的内容

Question

我有一个ContentControl,其内容由DataTemplateSelector基于属性Workspace确定.但是当数据模板被更改时,我必须根据ContentControl的初始大小和整个Window进行一些计算,所以我想知道它何时被加载.

<ContentControl Content="{Binding Path=Workspace}" ContentTemplateSelector="{StaticResource workspaceTemplateSelector}" />

ResourceDictionary中:

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
                    xmlns:vw="clr-namespace:Capgemini.Sag.KeyEm.View">

    <DataTemplate x:Key="keyboardTemplate"  >
        <vw:Keyboard/>
    </DataTemplate>

    <DataTemplate x:Key="welcomeTemplate">
        <vw:Welcome/>
    </DataTemplate>

    <vw:WorkspaceTemplateSelector            
        KeyboardTemplate="{StaticResource keyboardTemplate}"             
        WelcomeTemplate="{StaticResource welcomeTemplate}"        
        x:Key="workspaceTemplateSelector"/>
</ResourceDictionary>

DataTemplateSelector:

using Capgemini.Sag.KeyEm.ViewModel.Interfaces;

namespace Capgemini.Sag.KeyEm.View
{
    using System.Windows;
    using System.Windows.Controls;

    class WorkspaceTemplateSelector : DataTemplateSelector
    {
        public DataTemplate WelcomeTemplate { get; set; }
        public DataTemplate KeyboardTemplate { get; set; }

        public override DataTemplate SelectTemplate(object item, DependencyObject container)
        {
            if (item is IWelcomeViewModel)
                return WelcomeTemplate;
            if (item is IKeyboardViewModel)
                return KeyboardTemplate;
            return null;
        }
    }
}

Answer 1

您可以做的一件事是将数据模板内容包装在容器中并监听已加载的事件

<DataTemplate x:Key="keyboardTemplate">
        <Grid Loaded="Grid_Loaded">
            <vw:Welcome/>
        </Grid>
    </DataTemplate>

切换模板时将引发已加载事件。希望这会有所帮助。