BadImageFormatException

[rachelason]

HI All,
I am trying to call a c++ dll from a c# application. But i get BadImageFormatException.
The example i tried is one from this website
www.adp-gmbh.ch/win/misc/mingw/dll.html

Also i tried to create a simple dll in c++ , adding two integers and calling that in the c# ...no good - same error message..
This is my second day of learning c#, so not sure where to go from.
Any clue?

Thanks
Rach

[cjard]

Fancy posting some more code?
matt

[rachelason]

this is the example i used.... I am using visualstudio 2005 ...created the dll using win32 dll wizard.

<code>
mydll.h

int AddInt(int a , int b);




mydll.cpp

#include <stdio.h>
#include "mydll.h"

int AddInt(int a, int b){
int c;
c=a+b;
return c;
}


c# file

using System.Runtime.InteropServices;
using System;

class callDll{

[DllImport("<fullpathname>mydll.dll")]
private static extern int AddInt(int a, int b);

public static void Main() {
int aa = 100;
int bb= 150;
int cc;
cc=AddInt(aa, bb);
Console.WriteLine("Value returned is "+cc);
}
}


</code>

This is a simple program, though i am not doing any useful in here, i want to understand the concept of calling c++ dll from c# as i have a bigger project to work on.
All the files compile fine... no errors. Only at runtime, when to comes to call cc=AddInt(aa,bb) it errors with BadImageFormatException.

Thanks for your reply.

[Talikag]

Sorry, double posting...

[Talikag]

Next time use those: [CODE [/CODE (with ] in the end of the [/CODE & [CODE)...

emm.. I don't know what's the problem, but you can do this:

return a+b;

instead:

int c;
c=a+b;
return c;

Sorry :/

[rachelason]

Thanks for you reply..
i don't think the problem is with the way the value is returned.

Have i done everything right in the c# program? Why is the dll in badimageformat.....? any clues?

[rachelason]

Any suggestion anyone?

[jobin1983]

Rachael,

i dont think you can call the c++ code directly from c#. You need to create a CLR project to interface with the C++ project. Then you need to call the CLR project from C#. The CLR project will call the C++ code.

[memeloo]

Rachael,

i dont think you can call the c++ code directly from c#. You need to create a CLR project to interface with the C++ project. Then you need to call the CLR project from C#. The CLR project will call the C++ code.

this is not about thinking but about knowing... if you don't know don't post such nonsense

sure you can call native code from C#.

now to OP: I have still a similar problem http://www.codeguru.com/forum/showth...ormatException
though the post is quite old the same error comes. what's more, it happens to my own wrapper that I cannot use in C# because of this stupid error. there are no clues how to solve it.

I don't think anybody will be able to help us. this must be a very very very rare issue and no one ever has seen it