Wpf MEF导入不适用于具有多个活动屏幕的Shell

高I用户WPF/Calibur Micro/MEF。我尝试在shell中使用更活跃的屏幕。首先我定义屏幕-用户控件

屏幕视图模型

2.屏幕-视图模型

在第二个屏幕上，如果用户单击显示消息框的按钮，我只有一个按钮

没有最重要的部分外壳。外壳是WPF窗口

视图：

问题出在哪里

这里？导体。收集。激活

---

在您的

ShellViewModel

类型上，

ProjectInfo

和

Project

属性的类型应为

iProjectInfo视图模型

和

IProjectsViewModel

，因为这些是您导出的类型，您应该使用这些接口。

非常感谢，愚蠢的问题…我将视图模型类导出为接口…你是对的

public interface IProjectsViewModel
{

}
[Export(typeof(IProjectsViewModel))]
public class ProjectsViewModel:Screen,
    IProjectsViewModel
{

}

public interface IProjectInfoViewModel
{

}

[Export(typeof(IProjectInfoViewModel))]
public class ProjectInfoViewModel :Screen, 
    IProjectInfoViewModel
{
    [Import]
    internal IMessageBox MsgBox { get; set; }

    public void BtnClick()
    {
        MsgBox.ShowInfo("Btn click",string.Empty);
    }
}

<Window x:Class="CaliburnSkelet.Views.ShellView"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
        xmlns:Views="clr-namespace:CaliburnSkelet.Views" 
        xmlns:cal="clr-namespace:Caliburn.Micro;assembly=Caliburn.Micro" 
        Title="ShellView" Height="300" Width="300">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="200"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <!--<ContentControl x:Name="Projects" Grid.Column="0"/>
        <ContentControl x:Name="ProjectInfo" Grid.Column="1"/>-->
        <Views:ProjectsView  cal:View.Model="{Binding Projects}" 
                             Grid.Column="0"/>
        <Views:ProjectInfoView cal:View.Model="{Binding ProjectInfo}"
                               Grid.Column="1"/>
    </Grid>
</Window>

public interface IShellViewModel :IScreen
{
    ProjectInfoViewModel ProjectInfo { get; set; }
    ProjectsViewModel Project { get; set; }
}

[Export(typeof(IShellViewModel))]
public class ShellViewModel:Conductor<IScreen>.Collection.AllActive,
    IShellViewModel, IPartImportsSatisfiedNotification

{
    [Import]
    public ProjectInfoViewModel ProjectInfo { get; set; }

    [Import]
    public ProjectsViewModel Project { get; set; }

    public void OnImportsSatisfied()
    {
    }
}

  at CaliburnSkelet.BootStraper.MefBootStrapper.GetInstance(Type serviceType, String key) in E:\C# PROJECTS\CaliburnSkelet\CaliburnSkelet\BootStraper\MefBootStrapper.cs:line 69
   at Caliburn.Micro.Bootstrapper.DisplayRootViewFor(Type viewModelType)
   at Caliburn.Micro.Bootstrapper`1.OnStartup(Object sender, StartupEventArgs e)
   at System.Windows.Application.OnStartup(StartupEventArgs e)
   at System.Windows.Application.<.ctor>b__1(Object unused)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)

[Export(typeof(IShellViewModel))]
public class ShellViewModel:Conductor<IScreen>.Collection.AllActive,
    IShellViewModel, IPartImportsSatisfiedNotification

{
    //[Import]
    public ProjectInfoViewModel ProjectInfo { get; set; }

    //[Import]
    public ProjectsViewModel Project { get; set; }

    public void OnImportsSatisfied()
    {
        ProjectInfo=new ProjectInfoViewModel();
        Project=new ProjectsViewModel();
    }
}

        [Import]
        internal IMessageBox MsgBox { get; set; }

        public void BtnClick()
        {
//MsgBox is null
            MsgBox.ShowInfo("Btn click",string.Empty);
        }