c# - Issue integrating Action Delegate, Extensions, and Anonymous Type together -

so playing extensions, action , func in c# in trying mimic way ruby handles iteration on collections. idea objects (that enumerable) handle own iterations. got success extensions , delegates alone , have code below working expected;

using system; using system.collections.generic; using system.linq;  public class student{      public int studentid { get; set; }     public string studentname { get; set; }     public int age { get; set; } }  public static class extensions {     //for when need operations on items in collection     public static void foreach<t>(this ienumerable<t> items, action<t> action){          foreach(var item in items){             action(item);                    }     }      //for when want return modified collection     public static ienumerable<t> foreach<t>(this ienumerable<t> items, func<t,t> action){          foreach(var item in items){             yield return action(item);                   }     }  }    public class program {        public static void main()     {         ilist<student> studentlist = new list<student>() {              new student() { studentid = 1, studentname = "john", age = 12 },             new student() { studentid = 2, studentname = "moin", age = 13 },             new student() { studentid = 3, studentname = "bill", age =24 },             new student() { studentid = 4, studentname = "ram" , age =22 },             new student() { studentid = 5, studentname = "ron"  }          };          var selectresult = studentlist.select(s => s.studentname);           selectresult.foreach(name => console.writeline("name: {0}", name));          int = 1;         selectresult.foreach(name => string.format("name {0}: {1}", i++, name)).foreach(formattedname => console.writeline(formattedname));      } } 

then decided throw anonymous types mix , edited above code become below , that's problem is. keep getting run-time exception , can't seem figure out problem. kindly through or run see.

the error is; run-time exception (line 17): attempt method 'dynamicclass.callsite.target(system.runtime.compilerservices.closure, system.runtime.compilerservices.callsite, system.object)' access type '<>f__anonymoustype0`2' failed.

using system; using system.collections.generic; using system.linq;  public class student{      public int studentid { get; set; }     public string studentname { get; set; }     public int age { get; set; } }  public static class extensions {       public static void foreach<t,tint>(this ienumerable<dynamic> items, action<t,tint> action){          foreach(var item in items){             action(item.name, item.age);                     }     }  }    public class program {        public static void main()     {         ilist<student> studentlist = new list<student>() {              new student() { studentid = 1, studentname = "john", age = 12 },             new student() { studentid = 2, studentname = "moin", age = 13 },             new student() { studentid = 3, studentname = "bill", age =24 },             new student() { studentid = 4, studentname = "ram" , age =22 },             new student() { studentid = 5, studentname = "ron"  }          };          var selectresult = student in studentlist             select new {name = student.studentname, age = student.age};           selectresult.foreach((string name, int age) => console.writeline("name: {0}, age: {1}", name, age));      } } 

here's link on dotnet fiddle https://dotnetfiddle.net/zt7zb4