如何在C#中将名字和姓氏的首字母大写？

using System;

class Program
{
    static void Main()
    {
        string firstName = "john";
        string lastName = "doe";

        string capitalizedFirstName = firstName.Substring(0, 1).ToUpper() + firstName.Substring(1);
        string capitalizedLastName = lastName.Substring(0, 1).ToUpper() + lastName.Substring(1);

        Console.WriteLine("Capitalized first name: " + capitalizedFirstName);
        Console.WriteLine("Capitalized last name: " + capitalizedLastName);
    }
}

Capitalized first name: John
Capitalized last name: Doe