C# GetMethod vs GetRuntimeMethod

Question

I am using GetRuntimeMethod to get a method out of type. Everything works fine but I have noticed that there is a GetMethod. What is the difference between the two?

this.target.GetType().GetRuntimeMethod(
    "MethodName",
    new System.Type[0]
)?.Invoke(targetObject, null);

From the names I can only guess that GetRuntimeMethod works while the program is running. And GetMethod works during program compilation?

Are there any advantages of using one instead of another? (This last question can be deductible from the answer to what is the difference between the two of course)

Answer 1

GetMethod works on System.Type, the abstract base class for RuntimeType. GetRuntimeMethod calls GetMethod after validating the type is actually a RuntimeType (and not a (possibly user defined) child of Type), so it is slower than GetMethod. GetRuntimeMethod throws an exception if not passed a class derived from RuntimeType.

From the documentation for Type:

Type is an abstract base class that allows multiple implementations. The system will always provide the derived class RuntimeType. In reflection, all classes beginning with the word Runtime are created only once per object in the system and support comparison operations.

Also this article has further details on extending Type and when you might need a RuntimeType specifically.