WPF - 在视图模型中处理来自用户控件的事件 [英] WPF - Handling events from user control in View Model

问题描述

我正在使用 MVVM 模式构建 WPF 应用程序(这两种技术对我来说都是新技术).我将用户控件用于不包含业务逻辑的可重用功能的简单位，并使用 MVVM 模式来构建应用程序逻辑.假设一个视图包含触发事件的用户控件，并且我想向该事件添加一个事件处理程序.该事件处理程序应该在视图的视图模型中，因为它包含业务逻辑.问题是——视图和视图模型仅通过绑定连接；如何使用绑定连接事件处理程序?甚至有可能吗(我怀疑不是)?如果不是 - 我应该如何处理来自视图模型中的控件的事件?也许我应该使用命令或 INotifyPropertyChanged?

I’m building a WPF application using MVVM pattern (both are new technologies for me). I use user controls for simple bits of reusable functionality that doesn’t contain business logic, and MVVM pattern to build application logic. Suppose a view contains my user control that fires events, and I want to add an event handler to that event. That event handler should be in the view model of the view, because it contains business logic. The question is – view and the view model are connected only by binding; how do I connect an event handler using binding? Is it even possible (I suspect not)? If not – how should I handle events from a control in the view model? Maybe I should use commands or INotifyPropertyChanged?

推荐答案

一般来说，避免代码隐藏在 MVVM 中是一个很好的做法，就像在用户控件中使用事件一样.因此，如果可能，请使用 INotifyPropertyChanged 和 ICommand.

Generally speaking, it is a good MVVM-practice to avoid code in code behind, as would be the case if you use events in your user controls. So when possible, use INotifyPropertyChanged and ICommand.

话虽如此，根据您的项目和您的务实程度，有时使用背后的控件代码更有意义.

With that said, depending on your project and how pragmatic you are, some times it makes more sense to use the control's code behind.

我曾几次使用过这样的东西:

I have at a few occasions used something like this:

private void textBox1_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
    MyViewModel vm = this.DataContext as MyViewModel;
    vm.MethodToExecute(...);
}

你也可以考虑附加命令行为，有关此和实现的更多信息可在此处找到:

You could also consider Attached Command Behaviour, more info about this and implementations to find here:

触发双击事件从使用 MVVM 的 WPF ListView 项

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