When you need to check for null arguments

ThrowArgNullException.cs

public static void ThrowArgNullException(params object[] args)
{
    for (int i = 0; i < args.Count(); i++)
    {
        if (args[i] == null) throw new ArgumentNullException("Argument Number " + i);
    }
}

public static void ThrowArgNullException(string[] ArgNames, params object[] args)
{
    for (int i = 0; i < args.Count(); i++)
    {
        if (args[i] == null) throw new ArgumentNullException(ArgNames[i]);
    }
}