Question

I was wondering if its possible to call an event or method the first time a program starts up, and obviously on the first time. Is this possible to do in C#? If so could someone show some examples of how this is accomplished

Answer 1

You could use the MoveFileEx native method by specifying the DelayUntilReboot flag on some lock file:

class Program
{
    [Flags]
    enum MoveFileFlags
    {
        None = 0,
        ReplaceExisting = 1,
        CopyAllowed = 2,
        DelayUntilReboot = 4,
        WriteThrough = 8,
        CreateHardlink = 16,
        FailIfNotTrackable = 32,
    }

    [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    static extern bool MoveFileEx(
        string lpExistingFileName,
        string lpNewFileName,
        MoveFileFlags dwFlags
    );

    static void Main()
    {
        string lockFile = "foo.dat";
        if (!File.Exists(lockFile))
        {
            // that's a first run after the reboot => create the file
            File.WriteAllText(lockFile, "");

            // Mark the file for deletion after reboot
            MoveFileEx(lockFile, null, MoveFileFlags.DelayUntilReboot);

            Console.WriteLine("it's a first run");
        }
        else
        {
            // that's a consecutive run
            Console.WriteLine("it's a consecutive run");
        }
    }
}