how to know the number and type of parameters?
how to know the return type?
how to check whether the return type is void?
Jon Skeet
Use MethodInfo.ReturnType to determine the return type, and MethodBase.GetParameters() to find out about the parameters. (MethodInfo derives from MethodBase, so once you've got the MethodInfo via Type.GetMethod etc, you can use both ReturnType and GetParameters().)
If the method is void, the return type will be typeof(void):
if (method.ReturnType == typeof(void))
来源：https://stackoverflow.com/questions/3456994/how-to-use-net-reflection-to-determine-method-return-type-including-void-and