Create Dynamic Link Library in Vc++ for String operation and an VB application program to test it...

******************************************************* Instructions *****************************************************
(1) Make a folder named  C:\dll

(2) In that make a project named strdll ,make c++ file & copy strdll.cpp in it...

(3) Then copy vbpofdll in vbp prg & make form like dllpaint.jpg

(4) Also make def file as strdef like strdef.txt...

(5) make .dll & ENjoy with basic string operations...

**************************************************** strdll.cpp ***********************************************************

// strdll.cpp : Defines the entry point for the DLL application.
//


#include "stdafx.h"
#include "string.h"
#include "iostream.h"
#include "stdlib.h"


BOOL APIENTRY DllMain( HANDLE hModule, 
                       DWORD  ul_reason_for_call, 
                       LPVOID lpReserved
)
{
    return TRUE;
}


typedef struct {
char *a;
char *b;
}VB_UDT;


void WINAPI TestFunc(VB_UDT *pudt)
{

MessageBox(NULL, pudt->a, pudt->b, MB_ICONINFORMATION | MB_TASKMODAL);
MessageBox(NULL, strcat(pudt->a,pudt->b), pudt->b, MB_ICONINFORMATION | MB_TASKMODAL);
MessageBox(NULL, itoa(strlen(pudt->a),pudt->a,10), pudt->b, MB_ICONINFORMATION | MB_TASKMODAL);
MessageBox(NULL, itoa(strcmp(pudt->a, pudt->b),pudt->a,10), pudt->b, MB_ICONINFORMATION | MB_TASKMODAL);
MessageBox(NULL, strstr(pudt->a, pudt->b), pudt->b, MB_ICONINFORMATION | MB_TASKMODAL);
MessageBox(NULL, strcpy(pudt->a,pudt->b), pudt->b, MB_ICONINFORMATION | MB_TASKMODAL);


}

**************************************************** strdef.txt ***********************************************************

LIBRARY strdll

EXPORTS

TestFunc @1

*************************************************** vbpofdll.txt *********************************************************

Private Declare Sub TestFunc Lib "C:\dll\Debug\strdll.dll" (ByRef pudt As VB_UDT)

Private Type VB_UDT

   a As String

   b As String

End Type

Private Sub Command1_Click()

   Dim udt As VB_UDT

   udt.a = Text1.Text

   udt.b = Text2.Text

   Call TestFunc(udt)

End Sub

*************************************************** dllpaint.jpg *********************************************************