MVVM消息传递或事件或其他什么选择? [英] MVVM messaging or events or what other option out therer?

问题描述

我在MainViewModel中有一个菜单，现在选择了一个特定的menuItem，我想更新已经加载的视图的数据.

I have a menu in MainViewModel, now on selection of a particular menuItem I wanted to update data of a view which is already loaded.

即尽管MainViewModel中有一个viewModel实例，但是当我尝试通过该实例调用方法并更改data属性时，它不会在视图中显示更改.但是，当我使用viewModel的视图上的按钮通过Relay命令调用该方法时，会发生相同的变化.

i.e. although there's an instance of that viewModel in MainViewModel, when I try to invoke the method thru that instance and change the data property, it doesnt show the changes in the view. Whereas same changes occur when I invoke that method through relay command using a button on that viewModel's view.

现在就像需要从MainViewModel调用该viewModel的中继命令一样，我想这将解决问题，但是该怎么做呢?最简单的方法.我需要使用消息传递吗?

Now its like I need to invoke relay command of that viewModel from MainViewModel, I guess that will fix the problem, but how to do that? what's easiest way. Will i need to use messaging?

推荐答案

我尝试了MVVM Light Messenger类，它非常简单明了(保持ViewModels松散耦合)！最重要的是它可以工作

I tried MVVM Light messenger class, its quite straightforward and elegant (keeps ViewModels loosely coupled)!! and most importantly it works

code:

Send:
Messenger.Default.Send(stringParameter, "key_anything");

Register:
Messenger.Default.Register<string>(this, "key_anything", invokeFunction);

private void invokeFunction(string stringParamter)
{
//code goes here!
}

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