Connect to SolidWorks Message Pump to Handle Keystrokes and Accelerator Keys (C#)

This example shows how to connect to a SolidWorks message pump by creating, installing, and uninstalling a hook for a modeless dialog box or PropertyManager page for intercepting keystrokes and handling accelerator keys.

 

//Create, install, and uninstall a hook for a modeless dialog box

//or PropertyManager page for intercepting keystrokes and

//handling accelerator keys

using System;

using System.Runtime.InteropServices;

namespace WinHooks

{

    public class HookEventArgs : EventArgs

    {

        public int HookCode;    // Hook code

        public IntPtr wParam;   // WPARAM argument

        public IntPtr lParam;   // LPARAM argument

    }

    // Hook Types  

    public enum HookType : int

    {

        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

    }

    public class LocalWindowsHook

    {

        // Filter function delegate

        public delegate int HookProc(int code, IntPtr wParam,

           IntPtr lParam);

        // Internal properties

        protected IntPtr m_hhook = IntPtr.Zero;

        protected HookProc m_filterFunc = null;

        protected HookType m_hookType;

        // Event delegate

        public delegate void HookEventHandler(object sender, HookEventArgs e);

        // Event: HookInvoked

        public event HookEventHandler HookInvoked;

        protected void OnHookInvoked(HookEventArgs e)

        {

            if (HookInvoked != null)

                HookInvoked(this, e);

        }

        // Class constructor(s)

        public LocalWindowsHook(HookType hook)

        {

            m_hookType = hook;

            m_filterFunc = new HookProc(this.CoreHookProc);

        }

        public LocalWindowsHook(HookType hook, HookProc func)

        {

            m_hookType = hook;

            m_filterFunc = func;

        }        

        // Default filter function

        public int CoreHookProc(int code, IntPtr wParam, IntPtr lParam)

        {

            if (code < 0)

                return CallNextHookEx(m_hhook, code, wParam, lParam);

            // Let clients determine what to do

            HookEventArgs e = new HookEventArgs();

            e.HookCode = code;

            e.wParam = wParam;

            e.lParam = lParam;

            OnHookInvoked(e);

            // Yield to the next hook in the chain

            return CallNextHookEx(m_hhook, code, wParam, lParam);

        }

        // Install the hook

        public void Install()

        {

            m_hhook = SetWindowsHookEx(

                m_hookType,

                m_filterFunc,

                IntPtr.Zero,

                (int) AppDomain.GetCurrentThreadId());

        }

 

        // Uninstall the hook

        public void Uninstall()

        {

            UnhookWindowsHookEx(m_hhook);

        }

        #region Win32 Imports

        // Win32: SetWindowsHookEx()

        [DllImport("user32.dll")]

        protected static extern IntPtr SetWindowsHookEx(HookType code,

            HookProc func,

            IntPtr hInstance,

            int threadID);

        // Win32: UnhookWindowsHookEx()

        [DllImport("user32.dll")]

        protected static extern int UnhookWindowsHookEx(IntPtr hhook);

        // Win32: CallNextHookEx()

        [DllImport("user32.dll")]

        protected static extern int CallNextHookEx(IntPtr hhook,

            int code, IntPtr wParam, IntPtr lParam);

        #endregion

    }

}