验证泛型类型实现特定接口

Question

I have the following interfaces:

public interface IView<TViewModel>
{
    TViewModel ViewModel { get; set; }
}

public interface IViewModel : INotifyPropertyChanged
{
}

I would like to make sure that the generic TViewModel is always a class that implements interface IViewModel . I could do the following:

public interface IView
{
    IViewModel ViewModel { get; set; }
}

But then I would not have access to all the properties and methods of the specific class of ViewModel .

How can I make sure that TViewModel is always a class that implements interface IViewModel ?

Answer 1

Specify a generic type constraint using the where clause .

public interface IView<TViewModel> where TViewModel : IViewModel
{
    TViewModel ViewModel { get; set; }
}