在 MVVW 中，应该如何将事件从一个 ViewModel 传播到另一个 ViewModel？
我是 MVVW 模式的新手，所以如果我问一个非常基本的问题，你必须原谅我。
我有两个 ViewModel，我们将它们称为 TreeViewViewModel 和 ListViewViewModel。 TreeViewViewModel 绑定到其视图中的 IsSelected 属性。每当 IsSelected 发生变化时，我需要通知 ListViewViewModel 以便它可以更新其视图。
经过一些在线研究后，我发现了 EventAggregator，它看起来可能是一个很好的解决方案。
这是正确的解决方案吗？如果是这样，我应该如何实施？或者，我应该考虑更好的解决方案吗？下面是我认为 EventAggregator 如何集成到发布事件的 ViewModel 中的简化版本。
public class TreeViewViewModel : INotifyPropertyChanged
{
public bool IsSelected
{
get { return _isSelected; }
set
{
if (value == _isSelected)
return;
_isSelected = value;
OnPropertyChanged("IsSelected");
// Is this sane?
_eventAggregator.GetEvent<TreeViewItemSelectedEvent>().Publish(value);
}
}
protected virtual void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
I'm brand new to the MVVW pattern, so you'll have to forgive me if I'm asking a very basic question.
I have two ViewModels, we'll call them TreeViewViewModel and ListViewViewModel. TreeViewViewModel binds to an IsSelected property in its view. Whenever IsSelected changes, I need to inform ListViewViewModel so that it can update it's view.
After some research online, I've come across the EventAggregator which looks like it might be a good solution.
Is this the right solution? If so, how should I go about implementing this? Or, is there a better solution I should be considering? Below is a simplified version of how I think the EventAggregator might be integrated into the ViewModel publishing the event.
public class TreeViewViewModel : INotifyPropertyChanged
{
public bool IsSelected
{
get { return _isSelected; }
set
{
if (value == _isSelected)
return;
_isSelected = value;
OnPropertyChanged("IsSelected");
// Is this sane?
_eventAggregator.GetEvent<TreeViewItemSelectedEvent>().Publish(value);
}
}
protected virtual void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（3）
您当然可以使用事件聚合器，但您不需要事件聚合器来完成如此简单的事情。您只需让
ListViewViewModel监听TreeViewViewModel.PropertyChanged即可。You can certainly use an event aggregator, but you don't need one for something as simple as this. You can simply have
ListViewViewModellisten toTreeViewViewModel.PropertyChanged.EventAggregator 是一个不错的选择，您的代码对我来说看起来是正确的。
其他选项是 SharedService 或只是从一个视图模型直接引用另一个视图模型。
Prism 框架有一个关于这个主题的很好的文档：
http://msdn.microsoft.com/en-我们/library/ff921122(v=PandP.40).aspx
EventAggregator is a good option and your code look correct to me.
The other options would be SharedService or simply having direct reference from one viewmodel to another.
Prism framework has a nice documentation on this topic:
http://msdn.microsoft.com/en-us/library/ff921122(v=PandP.40).aspx
您的另一种选择是中介模式，这是一个示例：
Your other option is the mediator pattern, here is one example: http://marlongrech.wordpress.com/2009/04/16/mediator-v2-for-mvvm-wpf-and-silverlight-applications/