How to call generic method with a given Type object? [duplicate]

Question

I want to call my generic method with a given type object.

void Foo(Type t) {      MyGenericMethod<t>(); } 

obviously doesn't work.

How can I make it work?

Answer 1

Your code sample won't work, because the generic method expects a type identifier, not a an instance of the Type class. You'll have to use reflection to do it:

public class Example {      public void CallingTest()     {         MethodInfo method = typeof (Example).GetMethod("Test");         MethodInfo genericMethod = method.MakeGenericMethod(typeof (string));         genericMethod.Invoke(this, null);      }      public void Test<T>()     {         Console.WriteLine(typeof (T).Name);     } } 

Do keep in mind that this is very brittle, I'd rather suggest finding another pattern to call your method.

Another hacky solution (maybe someone can make it a bit cleaner) would be to use some expression magic:

public class Example {      public void CallingTest()     {         MethodInfo method = GetMethod<Example>(x => x.Test<object>());         MethodInfo genericMethod = method.MakeGenericMethod(typeof (string));         genericMethod.Invoke(this, null);      }      public static MethodInfo GetMethod<T>(Expression<Action<T>> expr)     {         return ((MethodCallExpression) expr.Body)             .Method             .GetGenericMethodDefinition();     }      public void Test<T>()     {         Console.WriteLine(typeof (T).Name);     } } 

Note passing the 'object' type identifier as a generic type argument in the lambda. Couldn't figure out so quickly how to get around that. Either way, this is compile-time safe I think. It just feels wrong somehow :/