WPF - Handling events from user control in View Model
I’m building a WPF application using MVVM pattern (both are new technologies for me). I use user controls for simple bits of reusable func开发者_StackOverflow社区tionality 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?
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
.
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.
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(...);
}
You could also consider Attached Command Behaviour, more info about this and implementations to find here:
Firing a double click event from a WPF ListView item using MVVM
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