How to get properties of type T in Task<T> using reflection?

Question

I am trying to get the properties of a return type of a method using reflection.

I am getting the return type of the method using MethodInfo.ReturnType , which yields my a type of Task<T> since my method is async . Using GetProperties on this type yields me with the properties belonging to Task : Result , Exception , AsyncState . However, I want to get the properties of the underlying type T.

Example for method with signature:

public async Task<MyReturnType> MyMethod()

var myMethodInfo = MyType.GetMethod("MyMethod");
var returnType = myMethodInfo.ReturnType; // Task<MyReturnType>
var myProperties = returnType.GetProperties(); // [Result, Exception, AsyncState]

How can I get the properties of the inner type T in Task in stead of the properties of Task?

Answer 1

You can determine if the type is a Task with the method GetGenericTypeDefinition() and get the generic type arguments with the property GenericTypeArguments .

In this case:

var myMethodInfo = MyType.GetMethod("MyMethod");
var returnType = myMethodInfo.ReturnType;

if (returnType.GetGenericTypeDefinition() == typeof(Task<>)) {
    var actualReturnType = returnType.GenericTypeArguments[0]; // MyReturnType
    var myProperties = actualReturnType.GetProperties(); // The properties of MyReturnType!
}