c# - Reflection error: "parameter type mismatch" -

i trying understand reflection in c# , trying following code work. first method (getusername) works second method (addgivennumbers) giving me exception error of "parameter type mismatch". created class library 2 methods , trying use reflection in main console application.

class library code:

namespace classlibrarydelete {     public class class1     {         public string getusername(string account)         {             return "my name " + account;         }          public int addgivennumbers(int num1, int num2)         {             return num1 + num2;         }     } } 

code in main console application:

using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks; using system.reflection;  namespace consoleapplicationdelete_reflection {     class program     {         static void main(string[] args)         {             assembly assemblyinstance = assembly.loadfrom(@"c:\users\xyz\desktop\debug\classlibrarydelete.dll");             type class1type = assemblyinstance.gettype("classlibrarydelete.class1");             object class1instance = activator.createinstance(class1type);             methodinfo getmethodfullname = class1type.getmethod("getusername");             string[] parameter = new string[1];             parameter[0] = "john doe";             string username = (string)getmethodfullname.invoke(class1instance, parameter);             console.writeline("user name = {0}", username);              assembly assemblyinstance2 = assembly.loadfrom(@"c:\users\xyz\desktop\debug\classlibrarydelete.dll");             type classtype2 = assemblyinstance.gettype("classlibrarydelete.class1");             object class1instance2 = activator.createinstance(classtype2);             methodinfo getmethodfullname2 = classtype2.getmethod("addgivennumbers");             //object[] parameters = new object[2];             //parameters[0] = 8;             //parameters[1] = 4;             object[] args2 = new object[] { 1, 2 };             object result = getmethodfullname.invoke(class1instance2, args2);             console.writeline("sum of 2 numbers {0}", result);             console.readline();         }     } } 

you have typo

object result = getmethodfullname.invoke(class1instance2, args2); 

you should have been targeting getmethodfullname2, otherwise you're trying execute first function (which takes 1 argument) 2 arguments.

working example: http://rextester.com/wbfyb30834