Multiple Main Methods in C#

Specify the Startup object in the Project Properties, Application tab.

Make sure the Main() method takes no parameters, or a single array of string ("string", not "String").  It should also returns nothing, or an int.  Otherwise, the main method(s) won't be shown in the dropdown list.

        static void Main(string[] args)
        {
 
        }

        static void Main()
        {
 
        }