Why am I getting an InvalidOperationException when I serialize an ArrayList?

Question

I am working CGI project using C programming and I am reading the login detail in form input fields and when I try to submit the form with empty fields it gives me 502 Bad Gateway CGI was not in CGI/1.1 complaint.note that i am redirecting to the same page I am reading the the fields.

Answer 1

XmlSerializer needs to know in advance what type of objects it will find in an ArrayList. To specify the type, use the XmlArrayItem attibute like this:

public class Person
{
public string Name;
public int Age;
}

public class Population
{
[XmlArrayItem(typeof(Person))] public ArrayList People;
}