using System.Runtime.InteropServices;

namespace GetMessageHookNet7
{
    public partial class Form1 : Form
    {
        const int WM_LBUTTONDOWN = 0x201;

        private delegate int HookProc(int code, IntPtr wParam, IntPtr lParam);

        [DllImport("user32.dll")]
        private static extern IntPtr SetWindowsHookEx(HookType code, HookProc func, IntPtr hInstance, int threadID);

        [DllImport("kernel32.dll")]
        static extern int GetCurrentThreadId();

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.button1.Enabled = false;
            int threadId = GetCurrentThreadId();
            SetWindowsHookEx(HookType.WH_GETMESSAGE, new HookProc(GetMessageHookProc), IntPtr.Zero, threadId);
        }

        private int GetMessageHookProc(int code, IntPtr wParam, IntPtr lParam)
        {
            if (code >= 0 && (long)wParam > 0)
            {
                Message msg = (Message)Marshal.PtrToStructure(lParam, typeof(Message));
                if (msg.Msg == WM_LBUTTONDOWN)
                {

                }
            }

            return 0;
        }

        private enum HookType
        {
            WH_MSGFILTER = -1,
            WH_JOURNALRECORD = 0,
            WH_JOURNALPLAYBACK = 1,
            WH_KEYBOARD = 2,
            WH_GETMESSAGE = 3,
            WH_CALLWNDPROC = 4,
            WH_CBT = 5,
            WH_SYSMSGFILTER = 6,
            WH_MOUSE = 7,
            WH_HARDWARE = 8,
            WH_DEBUG = 9,
            WH_SHELL = 10,
            WH_FOREGROUNDIDLE = 11,
            WH_CALLWNDPROCRET = 12,
            WH_KEYBOARD_LL = 13,
            WH_MOUSE_LL = 14
        }
    }
}