Get All Web Controls of a Specific Type on a Page

Question

I have been pondering how I can get all controls on a page and then perform a task on them in this related question:

How to Search Through a C# DropDownList Programm

Answer 1

This works if you use the form components from system.web.ui however this does not work when you use them from system.web.mvc apparently so i came up with the following work around.

for (Int32 idx = 0; idx < formCollection.Count; idx += 1)
                    {
                    String Name = formCollection.Keys[idx];
                    String value = formCollection[idx];

                    if (Name.Substring(0, 3).ToLower() == "chk")

                        {
                        Response.Write(Name + " is a checkbox 
");
                        }
                    else if (Name.Substring(0, 5).ToLower() == "txtar")
                        {
                        Response.Write(Name + " is a text area 
");
                        }
                    else if (Name.Substring(0, 2).ToLower() == "rd")
                        {
                        Response.Write(Name + " is a RadioButton 
");
                        }

                    }

This works for me however i found out that radio button if not selected is null so doesnt return anything which is ok i dont have to write anything to the database if it is null