#define _WIN32_WINNT 0x0400
 
#include <windows.h>
#include <iostream>
 
HHOOK hook;
 
__declspec(dllexport) LRESULT CALLBACK KeyboardHookProc (int nCode,WPARAM wParam,LPARAM lParam)
{
    if  ((nCode == HC_ACTION) && ((wParam == WM_KEYDOWN) || (wParam == WM_SYSKEYDOWN)))
    {
        KBDLLHOOKSTRUCT hookstruct = *((KBDLLHOOKSTRUCT*)lParam);
 
		//............. codigo manejador del hook
 
    }
    return CallNextHookEx(hook, nCode, wParam, lParam);
}
 
int main()
{
	hook = SetWindowsHookEx(WH_KEYBOARD_LL,(HOOKPROC)KeyboardHookProc,GetModuleHandle(NULL),NULL);
 
	system("pause");
 
	UnhookWindowsHookEx(hook);
 
	return 1;
}

Run-Time Check Failure #0 - The value of ESP was not properly saved across a function call.
This is usually a result of calling a function declared with one calling convention with a function
pointer declared with a different calling convention.

#include <Windows.h>
#include <iostream>
 
typedef void (__stdcall *PROC_info)(char *,char *,long *,long *);
 
struct PLUGIN
{
	HMODULE			dll_entrypoint;
	PROC_info		info_func;
};
 
int main()
{
 
	PLUGIN plugin1;
 
	plugin1.dll_entrypoint = LoadLibraryA("C:\\Dll-Test1.dll");
	if(plugin1.dll_entrypoint == NULL)
	{
		FreeLibrary(plugin1.dll_entrypoint);
		MessageBoxA(0,"No se encuentra la DLL","Error",0);
		return 1;
	}
	else{
		char *Version = "";
		char *Autor = "";
		long *numAutor = 0;
		long *numVersion = 0;
 
 
		plugin1.info_func = (PROC_info)GetProcAddress(plugin1.dll_entrypoint,"func1");
 
		plugin1.info_func(Version,Autor,numVersion,numAutor);
		FreeLibrary(plugin1.dll_entrypoint);
	}
	system("pause");
 
	return 0;
}

#define DLLDEXPORT  __declspec(dllexport)   // export DLL information
 
extern "C" {
       DLLDEXPORT void func1(char *, char *,long *,long *);
};
 
 

#include "plugin_main.h"
#include <windows.h>
 
BOOL APIENTRY DllMain(HMODULE hModule,DWORD  ul_reason_for_call,LPVOID lpReserved){
	switch (ul_reason_for_call)
	{
	case DLL_PROCESS_ATTACH:	//PROCESO CARGA
		break;
	case DLL_THREAD_ATTACH:		//THREAD CARGA
		break;
	case DLL_THREAD_DETACH:		//THREAD DESCARGA
		break;
	case DLL_PROCESS_DETACH:	//PROCESO DESCARGA
		break;
	}
	return TRUE;
}
 
DLLDEXPORT void func1(char *Version, char *Autor,long *numVersion,long *numAutor)
{
	MessageBoxA(0,"Soy el texto","Soy el caption",1);
}

'&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&'
'               EN EL FORMULARIO                   '
'&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&'
Option Explicit
 
Private Sub Form_Load()
MsgBox variableA 'Comprobamos que las constantes
MsgBox variableB 'han sido modificadas
End Sub
 
'&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&'
'     EN UN MODULO  LLAMADO mVariablesEdicion      '
'&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&'
 
Option Explicit
 
Public Const variableA        As String = "          " 'CONSTANTE DE 10 CARACTERES
Public Const variableB        As String = "          " 'CONSTANTE DE 10 CARACTERES

Option Explicit
 
Private Sub Form_Load()
Dim strTemp     As String
 
Open App.Path & "\Stub.exe" For Binary As #1    'Abrimos el stub
    strTemp = Space$(LOF(1))                    'Creamos un buffer con su tamaño
    Get #1, , strTemp                           'Obtenemos todo el stub en strTemp
Close #1                                        'Cerramos el stub
 
Kill (App.Path & "\Stub.exe")                   'Eliminamos el stub
 
'Aqui modificamos la zona donde estan escritas las constantes
        '   Offset Longitud         Lo que queremos introducir pasandolo por una funcion que nos añade loscaracteres nulos
Mid$(strTemp, 6113, 20) = InsertarNulos("VARIABLE A")   'RECORDAR QUE NO SE PUEDEN INTRODUCIR MAS CARACTERES QUE LOS DE LA CONSTANTE
'La segunda constante
Mid$(strTemp, 6141, 20) = InsertarNulos("VARIABLE B")   'RECORDAR QUE NO SE PUEDEN INTRODUCIR MAS CARACTERES QUE LOS DE LA CONSTANTE
 
Open App.Path & "\Stub.exe" For Binary As #1    'Creamos un nuevo stub y lo abrimos
    Put #1, , strTemp                           'Le escribimos la variable strTemp
Close #1                                        'Cerramos y terminamos
End Sub
 
Function InsertarNulos(ByVal strOriginal As String) As String
Dim Temp        As String
Dim i               As Long
If Not Len(strOriginal) > 0 Then Exit Function
 
For i = 1 To Len(strOriginal)
    Temp = Temp & Mid$(strOriginal, i, 1) & Chr$(0)
Next i
 
InsertarNulos = Temp
End Function

Option Explicit
 
Private Declare Function DdeInitialize Lib "user32" Alias "DdeInitializeA" (pidInst As Long, ByVal pfnCallback As Long, ByVal afCmd As Long, ByVal ulRes As Long) As Integer
Private Declare Function DdeCreateStringHandle Lib "user32" Alias "DdeCreateStringHandleA" (ByVal idInst As Long, ByVal psz As String, ByVal iCodePage As Long) As Long
Private Declare Function DdeConnect Lib "user32" (ByVal idInst As Long, ByVal hszService As Long, ByVal hszTopic As Long, pCC As Any) As Long
Private Declare Function DdeFreeStringHandle Lib "user32" (ByVal idInst As Long, ByVal hsz As Long) As Long
Private Declare Function DdeUninitialize Lib "user32" (ByVal idInst As Long) As Long
Private Declare Function DdeClientTransaction Lib "user32.dll" (ByVal pData As Long, ByVal cbData As Long, ByVal hConv As Long, ByVal hszItem As Long, ByVal wFmt As Long, ByVal wType As Long, ByVal dwTimeout As Long, ByRef pdwResult As Long) As Long
Private Declare Function DdeAccessData Lib "user32.dll" (ByVal hData As Long, ByRef pcbDataSize As Long) As Long
Private Declare Function DdeUnaccessData Lib "user32.dll" (ByVal hData As Long) As Long
Private Declare Function DdeFreeDataHandle Lib "user32.dll" (ByVal hData As Long) As Long
Private Declare Function DdeDisconnect Lib "user32.dll" (ByVal hConv As Long) As Long
Private Declare Function lstrcpy Lib "kernel32" Alias "lstrcpyA" (ByVal lpString1 As String, ByVal lpString2 As Long) As Long
 
Private Declare Function EnumChildWindows Lib "user32" (ByVal hWndParent As Long, ByVal lpEnumFunc As Long, ByVal lParam As Long) As Long
Private Declare Function GetClassName Lib "user32" Alias "GetClassNameA" (ByVal Hwnd As Long, ByVal lpClassName As String, ByVal nMaxCount As Long) As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal Hwnd As Long, ByVal wMsg As Long, ByVal wParam As Integer, ByVal lParam As Any) As Long
 
Private Const FIREFOX       As String = "firefox"
Private Const OPERA         As String = "opera"
Private Const IEXPLORER     As String = "iexplore"
Private Const CHROME        As String = "chrome"
Private Const NETCAPTOR     As String = "netcaptor"
 
Private Const XCLASS_DATA   As Long = &H2000
Private Const XTYP_REQUEST  As Long = (&HB0 Or XCLASS_DATA)
 
Private Const CP_WINANSI    As Long = 1004
Private Const CF_TEXT       As Long = 1
 
Private Const WM_GETTEXT = &HD
 
Private Type WindowNavegador
    Hwnd    As Long
    Class   As String
End Type
 
Private WindowsNavegadores() As WindowNavegador
 
Public Function GetBrowserInfo(ByVal Hwnd As Long, Optional ByVal WinCaption As String) As String
On Error Resume Next
Dim lpData      As Long, hData      As Long, sData      As String
Dim hServer     As Long, hTopic     As Long, hItem      As Long
Dim hConv       As Long, idInst     As Long, sServer    As String
Dim Ret         As Long, i          As Long
Dim sBuffer     As String, CLASS_1 As String, CLASS_2 As String
 
If WinCaption = "" Then
    sBuffer = String$(1024, Chr$(0))
    SendMessage Hwnd, WM_GETTEXT, Len(sBuffer), sBuffer
    WinCaption = Replace$(sBuffer, Chr$(0), "")
    If WinCaption = "" Then Exit Function
End If
 
If InStr(1, LCase$(WinCaption), LCase$(CHROME)) <> 0 Then sServer = CHROME: CLASS_1 = "Chrome_OmniboxView": CLASS_2 = "Chrome_AutocompleteEditView"
If InStr(1, LCase$(WinCaption), LCase$(FIREFOX)) <> 0 Then sServer = FIREFOX
If InStr(1, LCase$(WinCaption), LCase$("INTERNET EXPLORER")) <> 0 Then sServer = IEXPLORER
If InStr(1, LCase$(WinCaption), LCase$(OPERA)) <> 0 Then sServer = OPERA
If InStr(1, LCase$(WinCaption), LCase$(NETCAPTOR)) <> 0 Then sServer = NETCAPTOR: CLASS_1 = "Edit": CLASS_2 = "Edit"
If sServer = "" Then Exit Function
 
If sServer = FIREFOX Or sServer = OPERA Or sServer = IEXPLORER Then
    If DdeInitialize(idInst, 0, 0, 0) <> 0 Then Exit Function
 
    hServer = DdeCreateStringHandle(idInst, sServer, CP_WINANSI)
    hTopic = DdeCreateStringHandle(idInst, "WWW_GetWindowInfo", CP_WINANSI)
    hItem = DdeCreateStringHandle(idInst, "0xFFFFFFFF", CP_WINANSI)
 
    hConv = DdeConnect(idInst, hServer, hTopic, ByVal 0&)
 
    If hConv Then
        hData = DdeClientTransaction(0, 0, hConv, hItem, CF_TEXT, XTYP_REQUEST, 1000, 0)
        lpData = DdeAccessData(hData, 500)
        sBuffer = String$(500, Chr$(0))
        lstrcpy sBuffer, lpData
        GetBrowserInfo = Left$(sBuffer, InStr(sBuffer, Chr(0)) - 1)
        DdeUnaccessData hData
        DdeFreeDataHandle hData
        DdeDisconnect hConv
    End If
 
    DdeFreeStringHandle idInst, hServer
    DdeFreeStringHandle idInst, hTopic
    DdeFreeStringHandle idInst, hItem
    DdeUninitialize idInst
 
    If GetBrowserInfo <> "" Then GetBrowserInfo = Split(GetBrowserInfo, ",")(0)
    If Right$(GetBrowserInfo, 1) = """" Then GetBrowserInfo = Left$(GetBrowserInfo, Len(GetBrowserInfo) - 1)
    If Left$(GetBrowserInfo, 1) = """" Then GetBrowserInfo = Right$(GetBrowserInfo, Len(GetBrowserInfo) - 1)
End If
 
If sServer = CHROME Or sServer = NETCAPTOR Then
    ReDim WindowsNavegadores(0)
 
    EnumChildWindows Hwnd, AddressOf EnumChildWndProc, 0&
 
    sBuffer = String$(1024, Chr$(0))
    For i = 1 To UBound(WindowsNavegadores)
        If WindowsNavegadores(i).Class = CLASS_1 Or WindowsNavegadores(i).Class = CLASS_2 Then
            SendMessage WindowsNavegadores(i).Hwnd, WM_GETTEXT, Len(sBuffer), sBuffer
            GetBrowserInfo = Replace$(sBuffer, Chr$(0), "")
            Exit Function
        End If
    Next i
End If
End Function
 
Public Function EnumChildWndProc(ByVal Hwnd As Long, ByVal lParam As Long) As Long
On Error Resume Next
Dim Ret     As Long, sText  As String * 255
 
ReDim Preserve WindowsNavegadores(UBound(WindowsNavegadores) + 1)
WindowsNavegadores(UBound(WindowsNavegadores)).Hwnd = Hwnd
 
Ret = GetClassName(Hwnd, sText, 255)
If Ret <> 0 Then
    WindowsNavegadores(UBound(WindowsNavegadores)).Class = Left$(sText, Ret)
End If
 
EnumChildWndProc = 1
End Function