Reflection: How to get a generic method? [duplicate]

Question

Possible Duplicates:
How to use reflection to call generic Method?
Select Right Generic Method with Reflection

Hi there

Let's say I have two following two methods in a class:

public void MyMethod(object val) {} public void MyMethod<T>(T val) {} 

With reflection, I could get the first Method like this:

Type[] typeArray = new Type[1]; typeArray.SetValue(typeof(object), 1); var myMethod = myInstance.GetType().GetMethod("MyMethod", typeArray); 

But how can I get the second, generic method?

Answer 1

var myMethod = myInstance.GetType()                          .GetMethods()                          .Where(m => m.Name == "MyMethod")                          .Select(m => new {                                               Method = m,                                               Params = m.GetParameters(),                                               Args = m.GetGenericArguments()                                           })                          .Where(x => x.Params.Length == 1                                      && x.Args.Length == 1                                      && x.Params[0].ParameterType == x.Args[0])                          .Select(x => x.Method)                          .First(); 

Answer 2

I would do it like this:

var methods = from m in typeof(MyClass).GetMethods()               where m.Name == "MyMethod"                  && m.IsGenericMethodDefinition                let typeParams = m.GetGenericArguments()               let normalParams = m.GetParameters()                where typeParams.Length == 1 && normalParams.Length == 1                  && typeParams.Single() == normalParams.Single().ParameterType                  && !typeParams.Single().GetGenericParameterConstraints().Any()                select m;  var myMethod = methods.Single(); 

We're looking for a method called "MyMethod" that is a generic method with a single type-parameter having no constraints, and one 'normal' parameter of the same type as the type-parameter.

Obviously, if you're not looking to be very precise, you can just do the bare minimum to disambiguate, such as:

var myMethod = typeof(MyClass)               .GetMethods()               .Single(m => m.Name == "MyMethod" && m.IsGenericMethodDefinition);