我目前正在尝试使用WPF和MVVM,但最近遇到了一个我不知道如何解决的问题.我对此并不陌生,所以如果事情不应该如此,请告诉我.

我有一个ParentView及其ParentViewModel. ParentView拥有两个视图SubViewA和SubViewB,它们都有自己的ViewModel.这是我的ParentView.xaml：

<local:ViewBase.DataContext>
    <local:ParentViewModel x:Name="Model" />
</local:ViewBase.DataContext>

<Grid>
    <local:SubViewA Visibility="{Binding ElementName=Model, Path=SubViewAVisibility}" />
    <local:SubViewB Visibility="{Binding ElementName=Model, Path=SubViewBVisibility}" />
</Grid>

我想做什么：SubViewModelB具有绑定到SubViewB的属性.我想在ParentViewModel中发生某个事件时更改该属性.我想应该通过将SubViewModelB中的属性绑定到ParentViewModel中的属性来完成,但是我不确定如何？我在ParentView.xaml中尝试了以下内容：

<local:SubViewB Visibility="{Binding ElementName=Model, Path=SubViewBVisibility}" SomeProperty="{Binding ElementName=Model, Path=WhatIWantThePropertyToBe}" />

但这使我无处可去.
那么我该如何解决呢？我知道我可以通过MVVM light工具包中的消息传递来完成此操作,但这似乎与我要执行的操作不适当.有什么建议么？

谢谢

解决方法:

听起来像是解决EventAggregator模式的好方法.有一些很棒的实现,例如Microsoft Prism或TinyMessenger提供的实现(非常轻巧)

作为一个代码示例,您将执行以下操作(使用Prism,未经测试的代码)

public class ParentViewModel
{
    private IEventAggregator eventAggregator;

    public ParentViewModel(IEventAggregator eventAggregator)
    {
       this.eventAggregator = eventAggregator;
    }

    public void PublishSomeEvent()
    {
        // When a condition occurs, publish an event any subscribers 
        // that may be listening
        this.eventAggregator.GetEvent<SomeEvent>()
            .Publish(new SomeEvent("Hello World!")));
    }
}

public class SubViewModel
{
    private IEventAggregator eventAggregator;

    public SubViewModel(IEventAggregator eventAggregator)
    {
       eventAggregator.GetEvent<SomeEvent>.SomeEvent(OnSomeEventOccurred);
    }

    public void OnSomeEventOccurred(SomeEvent arg)
    {
        // This method called when ParentViewModel publishes the event
        Console.WriteLine(arg.OptionalMessage);
    }
}

您将需要单独的事件声明.例如,我用这个

public SomeEvent : CompositePresentationEvent<SomeEvent>
{
    public SomeEvent(string optionalMessage)
    {
        this.optionalMessage = optionalMessage;
    }

    public string OptionalMessage { get { return optionalMessage; } } 
}