createdll tutorial VC++ 2005

[Eran.Yasso@gmail.com]

Hi,

I need to develop DLL that exposes API. It should be accessed by C#.
Can any one please help me with that? any tutorial or link would be
greate.

TIA,

[Imm]

Re: createdll tutorial VC++ 2005


"""Eran.Yasso@g mail.com ÐÉÓÁÌ(Á):
"""

Hi,
>
I need to develop DLL that exposes API. It should be accessed by C#.
Can any one please help me with that? any tutorial or link would be
greate.
>
TIA,

Create dll in Visual C++ 2005:

1. "New Project\Win32\W in32 Console Application" create a new project.
-OK
2. "Applicatio n Settings\ Empty project" -FINISH
3. In "Solution Explorer" on "Source files" add new item "main.cpp"
4. Copy the text:

#include <windows.h>
#include <cstring>

int __declspec(dlle xport) FuncA(int i)
{
return i*10;
};
int __declspec(dlle xport) FuncB(int i)
{
return i*100;
};
char userLogin[80], userPassword[80];
bool __declspec(dlle xport) camomileLogin(c har user_name[], char
user_password[])
{

strcpy(userLogi n,user_name);
strcpy(userPass word,user_passw ord);
return true;
};
__declspec(dlle xport) char* camomileGetUser Login()
{
return userLogin;
};

5. In "Property Pages\Configura tion Properties\Gene ral\Configurati on
Type" select "Dynamic Library (.dll)" APPLY
6. Build.

You may use the tool ""C:\Progra m Files\Microsoft Visual Studio
8\Common7\Tools \Bin\Depends.Ex e""

Code for C# :

using System;
using System.Collecti ons.Generic;
using System.Componen tModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows. Forms;
using System.Runtime. InteropServices ;

namespace camomile_root
{
public partial class Form1 : Form
{
[DllImport("libc amomile.dll", EntryPoint = "?FuncA@@YAHH@Z ")]
public static extern int FuncA(int x);
[DllImport("libc amomile.dll", EntryPoint = "?FuncB@@YAHH@Z ")]
public static extern int FuncB(int x);
[DllImport("libc amomile.dll", EntryPoint =
"?camomileGetUs erLogin@@YAPADX Z")]
public static extern string camomileGetUser Login();
[DllImport("libc amomile.dll", EntryPoint =
"?camomileLogin @@YA_NQAD0@Z", CharSet = CharSet.Ansi, CallingConventi on
= CallingConventi on.StdCall)]
public static extern bool camomileLogin(s tring user_name,
string user_password);

public Form1()
{
InitializeCompo nent();
}

private void okey_Click(obje ct sender, EventArgs e)
{
int answer = FuncA(57);
userLogin.Text = answer.ToString ();
int answer1 = FuncB(57);
userPassword.Te xt = answer1.ToStrin g();
string s = "user";
string s2 = "passwd";
camomileLogin(s ,s2);
string answer2 = camomileGetUser Login();
userPassword.Te xt = answer2;

}

private void cancelButton_Cl ick(object sender, EventArgs e)
{
Close();
}
}
}

[Bruno van Dooren [MVP VC++]]

Re: createdll tutorial VC++ 2005

Not an ideal solution, because you have to import mangled names, which can
be annoying to figure out, and the mangled names change if you add a funcion
parameter.
A better method is so insure that the function names are not mangled.
The easiest ways to do this are either change

int __declspec(dlle xport) FuncA(int i)

to

extern "c"
{
__declspec(dlle xport) int __cdecl FuncA(int i);
}

int FuncA(int i)
{
//..implementatio n here
}
or add a DEF file to your project and declare function exports in there.
that way you can also export unmangled functions that use the stdcall
calling convention.

[DllImport("libc amomile.dll", EntryPoint = "?FuncA@@YAHH@Z ")]
public static extern int FuncA(int x);

Do not foget to use the CallingConventi on attribute to specify the calling
convention that was used. otherwise there will be an access violation.

--

Kind regards,
Bruno van Dooren
bruno_nos_pam_v an_dooren@hotma il.com
Remove only "_nos_pam"

[Rich]

Re: createdll tutorial VC++ 2005

Eran.Yasso@gmai l.com wrote:

Hi,
>
I need to develop DLL that exposes API. It should be accessed by C#.
Can any one please help me with that? any tutorial or link would be
greate.
>
TIA,

Here is a link to a good tutorial on setting up a project to build an
unmanaged DLL:

http://www.codeguru.com/cpp/cpp/cpp_mfc/tutorials/article.php/c9855/

I followed this article and created a very simple test DLL (using a
..DEF file for exporting functions).


Here is the C++ file:

#include <iostream>
#include "Test_DLL.h "

#ifdef __cplusplus
extern "C" {
#endif

int Add(int a, int b) {
return( a + b );
}

void Function( void ) {
std::cout << "DLL Called!" << std::endl;
}

#ifdef __cplusplus
}
#endif


Here is the Header file:

#ifndef _DLL_TUTORIAL_H _
#define _DLL_TUTORIAL_H _
#include <iostream>

#ifdef __cplusplus
extern "C" {
#endif

int Add(int a, int b);
void Function( void );

#ifdef __cplusplus
}
#endif

#endif


Here is the DEF file:

LIBRARY Test_DLL
EXPORTS
Add @1
Function @2



Once you have your unmanaged DLL, test it from an unmanaged application
to make sure everything works.
This builds to a .DLL file and a .LIB file. We need these two files
plus the header file for an application to use the DLL.
Here is a simple test program that tests our DLL:
#include <iostream>
#include "Test_DLL.h "

int main()
{
Function();
std::cout << Add(32, 58) << "\n";
return(1);
}



Now you need to build a MANAGED DLL (assembly) so you can call your
functions from C# (or VB or any other .NET language).
Here is the managed C++ file for the managed DLL:

using namespace System::Runtime ::InteropServic es;

[DllImport("Test _DLL", EntryPoint="Add ")]
extern "C" int Add(int a, int b);

[DllImport("Test _DLL", EntryPoint="Fun ction")]
extern "C" void Function( void );

namespace Test_DLL_CLR {

public ref class Test_DLL_Class {
public:
// Function: Add
int Add_clr(int a, int b)
{
return( Add( a, b) );
}

// Function: Function
void Function_clr(vo id)
{
Function();
}
};
}


Once you have your managed DLL, you can include it in your C# project
as a reference. You should now be able to use the namespace defined in
the managed DLL (along with everything defined in that namespace).
Here is C# code that uses the managed DLL:

using System;
using System.Collecti ons.Generic;
using System.Text;
using Test_DLL_CLR;

namespace Test_DLL_CLR_ap p_cs
{
class Program
{
static void Main(string[] args)
{
Test_DLL_Class myclass = new Test_DLL_Class( );
int val;

Console.WriteLi ne("C# Test_DLL_CLR Test Program");

myclass.Functio n_clr();
val = myclass.Add_clr (123, 456);

Console.WriteLi ne("val = " + val);

Console.WriteLi ne("Finished.") ;
}
}
}

[Ben Voigt]

Re: createdll tutorial VC++ 2005


<Eran.Yasso@gma il.comwrote in message
news:1164315840 .407737.226460@ f16g2000cwb.goo glegroups.com.. .

Hi,
>
I need to develop DLL that exposes API. It should be accessed by C#.

Does it need to be used from any non-.NET language?

Can any one please help me with that? any tutorial or link would be
greate.

building a C++/CLI assembly for consumption by C# is trivially easy, just do
new project -C++ -CLR -Class Library, then add some "ref class"
definitions (there's a wizard for that too, right click the C++ project and
do Add -New Class).

>
TIA,
>

[Eran.Yasso@gmail.com]

Re: createdll tutorial VC++ 2005


Imm wrote:

"""Eran.Yasso@g mail.com ÐÉÓÁÌ(Á):
"""

Hi,

I need to develop DLL that exposes API. It should be accessed by C#.
Can any one please help me with that? any tutorial or link would be
greate.

TIA,

>
Create dll in Visual C++ 2005:
>
1. "New Project\Win32\W in32 Console Application" create a new project.
-OK
2. "Applicatio n Settings\ Empty project" -FINISH
3. In "Solution Explorer" on "Source files" add new item "main.cpp"
4. Copy the text:
>
#include <windows.h>
#include <cstring>
>
int __declspec(dlle xport) FuncA(int i)
{
return i*10;
};
int __declspec(dlle xport) FuncB(int i)
{
return i*100;
};
char userLogin[80], userPassword[80];
bool __declspec(dlle xport) camomileLogin(c har user_name[], char
user_password[])
{
>
strcpy(userLogi n,user_name);
strcpy(userPass word,user_passw ord);
return true;
};
__declspec(dlle xport) char* camomileGetUser Login()
{
return userLogin;
};
>
5. In "Property Pages\Configura tion Properties\Gene ral\Configurati on
Type" select "Dynamic Library (.dll)" APPLY
6. Build.
>
You may use the tool ""C:\Progra m Files\Microsoft Visual Studio
8\Common7\Tools \Bin\Depends.Ex e""
>
Code for C# :
>
using System;
using System.Collecti ons.Generic;
using System.Componen tModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows. Forms;
using System.Runtime. InteropServices ;
>
namespace camomile_root
{
public partial class Form1 : Form
{
[DllImport("libc amomile.dll", EntryPoint = "?FuncA@@YAHH@Z ")]
public static extern int FuncA(int x);
[DllImport("libc amomile.dll", EntryPoint = "?FuncB@@YAHH@Z ")]
public static extern int FuncB(int x);
[DllImport("libc amomile.dll", EntryPoint =
"?camomileGetUs erLogin@@YAPADX Z")]
public static extern string camomileGetUser Login();
[DllImport("libc amomile.dll", EntryPoint =
"?camomileLogin @@YA_NQAD0@Z", CharSet = CharSet.Ansi, CallingConventi on
= CallingConventi on.StdCall)]
public static extern bool camomileLogin(s tring user_name,
string user_password);
>
public Form1()
{
InitializeCompo nent();
}
>
private void okey_Click(obje ct sender, EventArgs e)
{
int answer = FuncA(57);
userLogin.Text = answer.ToString ();
int answer1 = FuncB(57);
userPassword.Te xt = answer1.ToStrin g();
string s = "user";
string s2 = "passwd";
camomileLogin(s ,s2);
string answer2 = camomileGetUser Login();
userPassword.Te xt = answer2;
>
}
>
private void cancelButton_Cl ick(object sender, EventArgs e)
{
Close();
}
}
}

Hi All and thanks for your reply,

Imm,I have question regarding your answer.

I changed the functions name in the dll. when i changed the Entry
points in C#, with the same name, I got massage that the entry points
can't be found. I changed function FuncA to GetPosition and FuncB to
SetPosition. I also changed in C#:
[DllImport("Yass o.dll", EntryPoint = "?FuncA@@YAHH@Z ")]
public static extern int FuncA(int x);
to
[DllImport("Yass o.dll", EntryPoint = "?GetPosition@@ YAHH@Z")]
public static extern int GetPosition(int x);

Why is it not working?
TIA,

[Imm]

Re: createdll tutorial VC++ 2005

Hi All and thanks for your reply,

>
Imm,I have question regarding your answer.
>
I changed the functions name in the dll. when i changed the Entry
points in C#, with the same name, I got massage that the entry points
can't be found. I changed function FuncA to GetPosition and FuncB to
SetPosition. I also changed in C#:
[DllImport("Yass o.dll", EntryPoint = "?FuncA@@YAHH@Z ")]
public static extern int FuncA(int x);
to
[DllImport("Yass o.dll", EntryPoint = "?GetPosition@@ YAHH@Z")]
public static extern int GetPosition(int x);
>
Why is it not working?
TIA,

I have not problem. You mayby don't rewrite your new version dll and
you C# see old version.

See my source code. You passible found your misteke. I changed FuncA to
GetPosition and rewrite dll to folder with C# executable file. This is
All.

See other answers. its very good.

#include <windows.h>
#include <cstring>
int __declspec(dlle xport) GetPosition(int i) // it was change
{ return i*10; };
int __declspec(dlle xport) FuncB(int i)
{ return i*100; };
char userLogin[80], userPassword[80];
bool __declspec(dlle xport) camomileLogin(c har user_name[], char
user_password[])
{ strcpy(userLogi n,user_name);
strcpy(userPass word,user_passw ord);
return true;
};
__declspec(dlle xport) char* camomileGetUser Login()
{
return userLogin;
};

C# :

using System;
using System.Collecti ons.Generic;
using System.Componen tModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows. Forms;
using System.Runtime. InteropServices ;
namespace testdllCSharp
{ public partial class Form1 : Form
{ [DllImport("test dll.dll", EntryPoint = "?GetPosition@@ YAHH@Z")]

public static extern int GetPosition(int x);// <--- it was
change ^
[DllImport("test dll.dll", EntryPoint = "?FuncB@@YAHH@Z ")]
public static extern int FuncB(int x);
[DllImport("test dll.dll", EntryPoint =
"?camomileGetUs erLogin@@YAPADX Z")]
public static extern string camomileGetUser Login();
[DllImport("test dll.dll", EntryPoint =
"?camomileLogin @@YA_NQAD0@Z", CharSet = CharSet.Ansi, CallingConventi on
= CallingConventi on.StdCall)]
public static extern bool camomileLogin(s tring user_name,
string user_password);
public Form1()
{ InitializeCompo nent(); }
private void button1_Click(o bject sender, EventArgs e)
{ int answer = GetPosition(57) ;// it was change
userLogin.Text = answer.ToString ();
int answer1 = FuncB(57);
userPassword.Te xt = answer1.ToStrin g();
string s = "user";
string s2 = "passwd";
camomileLogin(s , s2);
string answer2 = camomileGetUser Login();
userPassword.Te xt = answer2;
}
}
}