c# console: How to ReadLine without the need of pressing [Enter]

Question

My c# console application is used as a login for my c# form application, the problem is, in my c# console app i haven't been able to figure out a way to ReadLine without the need of pressing Enter because i need to detect whether F2 or Enter is pressed then ReadLine without needing user to press Enter again. For example, if i wanted to detect if F2 is pressed i would need to wait until F2 is pressed until I'm able to ReadLine, Hopefully this question was worded in a way that it makes sense, I'm sure you can tell I'm quite a 'noob' at c#.
Example of my problem:

static void Main()
{
    var KP = Console.ReadKey();
    if (KP.Key == ConsoleKey.F2)
    {                                    
        //User Presses F2                
    }      
    else if (KP.Key == ConsoleKey.Enter)
    {
        string UserName = ReadLineWithoutPressingEnter();//Just a example
        //ReadLine without needing to press enter again
    }                            
}                         

Thank you for your time.

Answer 1

Save the result from ReadKey and then just do a ReadLine:

   public static void Main(string[] args)
    {
        var KP = Console.ReadKey();
        if (KP.Key == ConsoleKey.F2)
        {
            return;               
        }

        string UserName = KP.KeyChar + Console.ReadLine();

        Console.WriteLine(UserName);
        Console.ReadLine();
    }

Answer 2

You've already found Console.ReadKey(). That's a start. You'll need to also build a state machine around this function to return a completed string at the end of the line, but this method is the key to making that work. Don't forget to handle things like backspace and delete.