Solved

Using c++ lib file in c#

Posted on 2010-09-02
5
533 Views
Last Modified: 2012-06-27
Hello,

I have a lib file written in unmanaged c++. (I have access to the source code.)

How can i use it in c# ?
I think that i need to write a wrapper and convert it to a managed dll.
But i don't know where to start.

Can you please show me a working example source code or good links ?
thanks.


0
Comment
Question by:parabellum
5 Comments
 
LVL 40

Accepted Solution

by:
evilrix earned 400 total points
ID: 33584520
You can build managed and unmanaged together in one assembly using mixed mode assemblies and IJW (It Just works). You can then access the unmanaged code via the managed C++.

http://msdn.microsoft.com/en-us/library/x0w2664k.aspx

"Mixed assemblies are capable of containing both unmanaged machine instructions and MSIL instructions. This allows them to call and be called by .NET components, while retaining compatibility with components that are entirely unmanaged. Using mixed assemblies, developers can author applications using a mixture of managed and unmanaged functionality. This makes mixed assemblies ideal for migrating existing Visual C++ applications to the .NET Platform."

Below is an example of IJW at work.This simple bit of code shows just how simple it is to use IJW to interface between managed and unmanaged code, no need to mess with GUIDs or other nasty COM things.
// C++ (all in one IJW assembly)
 
#include <iostream>
 
namespace UnmanagedCode
{
        void foo()
        {
                std::cout << "Hello, world" << std::endl;
        }
}
 
namespace ManagedCode
{
        public ref class fooWrapper
        {
        public:
                static void foo()
                {
                        UnmanagedCode::foo();
                }
        };
}
 
 
// C# code (seperate assembly)
 
using System;
using System.Collections.Generic;
using System.Text;
 
namespace scratchcs
{
    class Program
    {
        static void Main(string[] args)
        {
            ManagedCode.fooWrapper.foo();
        }
    }
}

Open in new window

0
 
LVL 14

Assisted Solution

by:Daniel Junges
Daniel Junges earned 100 total points
ID: 33584611
0
 
LVL 1

Expert Comment

by:sureshmunugoti
ID: 33584963

Suppose you are having the unmanged library called TestLib.dll
Then Your managed code should be as shown below...

using System;
using System.Runtime.InteropServices;    
class Consume
{
    [DllImport("TestLib.dll")]
    public static extern void Hello ();

    static void Main ()
    {
                Hello ();
    }
}
0
 
LVL 12

Expert Comment

by:w00te
ID: 33586420
>>ManagedCode.fooWrapper.foo();

How does the C# assembly know the ManagedCode namespace in that example?  I'm guessing it works but I don't know whats happening in the background and I'm interested :)
0
 
LVL 40

Expert Comment

by:evilrix
ID: 33586954
>> How does the C# assembly know the ManagedCode namespace in that example?

The assembly just needs to be referenced by the C# code (just like any assembly) and that's it. Once a .Net assembly is referenced it is visible globally, unlike unmanaged C++ there things have to be declared.
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Media.Imaging 1 24
Keyboard 2 41
Gaming Software 1 19
How to increment counter variables in ANSI  C (Not C# or C++). 9 23
Article by: SunnyDark
This article's goal is to present you with an easy to use XML wrapper for C++ and also present some interesting techniques that you might use with MS C++. The reason I built this class is to ease the pain of using XML files with C++, since there is…
Summary: Persistence is the capability of an application to store the state of objects and recover it when necessary. This article compares the two common types of serialization in aspects of data access, readability, and runtime cost. A ready-to…
The goal of the video will be to teach the user the concept of local variables and scope. An example of a locally defined variable will be given as well as an explanation of what scope is in C++. The local variable and concept of scope will be relat…
The viewer will learn how to user default arguments when defining functions. This method of defining functions will be contrasted with the non-default-argument of defining functions.

820 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question