Question

I am looping thru the ObjectStateEntry of EF so I can access enrty.Entity, I am doing some static validation on the poco classes and i want to also do business rule validation so i created a library to do that, now i have this line of code that expect a type excample Customer..

 MyEntityValidator<needtypehere> ev = new MyEntityValidator<needtyehere>(new EntityValidator());

so I am having problem passing type where i mentiened ‘needtypehere’. I tried entry.Entity.GetType() but not working . Again this is the signiture of the method

GetErrors(this ObjectStateEntry entry)

Answer 1

To invoke generics from a Type instance, you would have to use:

Type closedType = typeof(MyEntityValidator<>)
         .MakeGenericType(entry.Entity.GetType());
object obj = Activator.CreateInstance(closedType);

which is… awkward – as you then need to do lots of additional work with reflection. Alternatively, you can call into a generic method that does the code:

public static void InvokeGeneric<T>(...) {
    MyEntityValidator<T> ev = new MyEntityValidator<T>(
        new EntityValidator());
    ... etc; lots more code that uses ev
}
...
typeof(ContainingType).GetMethod("InvokeGeneric").MakeGenericMethod(
    entry.Entity.GetType()).Invoke(null, args);