Sending Keyboard Macro Commands to Game Windows

Private Const WM_KEYDOWN As Integer = &H100
Private Const WM_KEYUP As Integer = &H101

private static int WM_KEYDOWN = 0x100
private static int WM_KEYUP = 0x101

class SendKeySample
{
    private static Int32 WM_KEYDOWN = 0x100;
    private static Int32 WM_KEYUP = 0x101;

    [return: MarshalAs(UnmanagedType.Bool)]
    [DllImport("user32.dll", SetLastError = true)]
    static extern bool PostMessage(IntPtr hWnd, int Msg, System.Windows.Forms.Keys wParam, int lParam);

    [DllImport("user32.dll", SetLastError = true)]
    private static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);

    public static IntPtr FindWindow(string windowName)
    {
        foreach (System.Diagnostics.Process p in System.Diagnostics.Process.GetProcesses())
        {
            if (p.MainWindowHandle != IntPtr.Zero && p.MainWindowTitle.ToLower() == windowName.ToLower())
                return p.MainWindowHandle;
        }

        return IntPtr.Zero;
    }

    public static IntPtr FindWindow(IntPtr parent, string childClassName)
    {
        return FindWindowEx(parent, IntPtr.Zero, childClassName, string.Empty);
    }

    public static void SendKey(IntPtr hWnd, System.Windows.Forms.Keys key)
    {
        PostMessage(hWnd, WM_KEYDOWN, key, 0);

    }
}

var hWnd = SendKeySample.FindWindow("Untitled - Notepad");
        var editBox = SendKeySample.FindWindow(hWnd, "edit");

        SendKeySample.SendKey(editBox, Keys.A);