1.

The first step in this walk-through is to create lib file that we want to expose in our managed code.  To do this, create a blank Visual Studio Solution and give it a name.

2.

Once we have a solution, lets add a C++ static library project to the solution.  To do this, go to Solution Explorer and right click on the solution.  On the context menu, select “Add -> New Project”.   This should bring up the “Add New Project” dialog.  Add a new C++ Win32 project.  Give it a name, and select OK.

3.

When the “Win32 Application Wizard” comes up, select the “Next” button.  Under Application Type, select “Static Library”.  Also, for this example I turned off “Precompiled header”.  And select “Finish”.

4.

Go to the Solution Explorer again, and right click on your static library project, and select “Add -> Class…”.  This will bring up the “Add Class” dialog, select “Add”.

5.

Fill in the information in the “Generic C++ Class Wizard”.  Select “Finish”.

6.

Modify the resulting AddClass.h file to look like this:

7.

Let’s provide the implementation in AddClass.cpp:

At this point, you should be able to successfully compile our example lib file.

8.

OK – we are now setup for the rest of this example.  We have a lib file and a header file that we will expose to our managed application.  To do this, we will create a new CLR class library, using C++/CLI.  So, go back to the Solution Explorer and right click on the solution.  Select “Add -> New Project…”.   In the Project Types treeview, select “Visual C++ -> CLR”.  In the Templates pane, select “Class Library”, and give it a name and select OK.

9.

Now we need to set a couple of project properties to be able to use the lib file.  So, in Solution Explorer, right click on the ClrWrapper project and select Properties.  In the “ClrWrapper Property Pages”,  select “All Configurations” in the Configuration drop down.  Then, select “Configuration Properties -> C/C++ -> General”.  Modify the “Additional Include Directories” property, to point to the directory containing the header file for the .lib.

Selecting the browse button will bring up the “Additional Include Directories” dialog.

Clicking in the list at the top, will again give you a browse button that will bring up a folder browser dialog.  Use the folder browser to point to the directory where your lib files header is in.

Select OK, then Apply in the “ClrWrapper Property Pages”.

10.

Now, we need to tell the linker where the lib file is.  We could do this by adding a project reference to the AddTwoNumbersLib project – but, since we are trying to simulate us only having the lib, we’ll do it the hard way!

With the “ClrWrapper Property Pages” dialog still open, “Configuration Properties -> Linker -> Input”.

Select, “Additional Dependencies” and then the browse button that appears.  This will bring up the “Additional Dependencies” dialog.

In the list at the top, insert the full path to the lib file (make sure it’s in quotes).

Select OK.  And OK again on the “ClrWrapper Property Pages”.

11.

Now, lets create our wrapper.  Modify the following files

stdafx.h

ClrWrapper.h

ClrWrapper.cpp

With that done, you should be able to compile the solution.

12.

Now, create a managed project in the language of your choice – C# or VB, and add a reference to your the ClrWrapper.dll.  Once done, you should be able to write, compile, and run code like the following:

C#

VB

1.

Since there is no IDE support for the JScript.NET language, create and save the Evaluator.js file in the external text editor of your choice. 

2.

Use the “Visual Studio 2008 Command Prompt” (Start -> Programs -> Microsoft Visual Studio 2008 -> Visual Studio Tools) to navigate to the directory that contains the Evaluator.js file.  Once there, compile the source, like this:

Ok, so I didn’t use the VS command prompt   I used the Windows PowerShell console.  I translated the bat file that the VS command prompt uses and put it in my $PROFILE.

3.

Now, create your Visual Basic or C# project.  Right click on your project in the Solution Explorer, and select “Add Reference…”.  On the .NET tab select Microsoft.JScript:

4.

Again, Right click on your project in the Solution Explorer, and select “Add Reference…”.   Select the “Browse” tab, and find and select the Evaluator.dll that we just compiled:

5.

Let’s write some code to use the dll.

C#

using System;

namespace CSharpExample

{

    class Program

    {

        static void Main ( string[] args )

        {

            string expression = string.Format ( "(Math.pow({0}, {1}) * {2}) / {3}", 50, 2, 3.5, 16.25 );

            Console.WriteLine ( Calculate ( expression ) );

        }

        static decimal Calculate ( string expression )

        {

            return Convert.ToDecimal ( new Evaluator ().Evaluate ( expression ) );

        }

    }

}

VB

Option Strict On

Option Explicit On

Module VBExample

    Sub Main()

        Dim expression As String = String.Format("(Math.pow({0}, {1}) * {2}) / {3}", 50, 2, 3.5, 16.25)

        Console.WriteLine(Calculate(expression))

    End Sub

    Function Calculate(ByVal expression As String) As Decimal

        Return Convert.ToDecimal(New Evaluator().Evaluate(expression))

    End Function

End Module

1.

The first step is to create a new Visual C++ solution.  Click on “File -> New -> Project…”.  This brings up the “New Project” dialog.  In the “Project Types” pane, select “Other Languages -> Visual C++ -> Win32″.  Then from the “Templates” pane on the right, select “Win32 Console Application”.  Give the project a name (I called mine CallCSharpCodeSample) and select the “OK” button.

When the “Application Settings Wizard” dialog appears, select the “Finish” button. The Console project just created will become the host application to test out the dll.

2.

Add a C# Class Library project.  This library will represent the existing .NET assembly that needs to exposed via the C++ dll.  Go to Solution Explorer, and right click on the solution and select “Add -> New Project…”.  In the “Project types” pane of the “Add New Project” dialog,  select “Visual C# -> Windows”.  In the “Templates” pane select “Class Library”.  Give the library a name, and then select the “OK” button.

3.

Rename the default Class1.cs to AddClass.cs and allow the IDE to rename your class.  Insert a method to add two integers.  Your code should look something like this:

4.

Setup is now complete and you’re ready to create the dll.  Right click on the solution in Solution Explorer, select “Add -> New Project…”.  Add a new C++ Win32 project from the “Add New Project” dialog.  And give it a name and select the “OK” button.

5.

You will again be presented with the “Application Settings Wizard”.  Select the “Next” button and set the project options as shown below.  Select the “Finish” button.

6.

When the MyDll project is created, Visual Studio adds some unneeded code to “MyDll.h” and “MyDll.cpp”.  Edit these files to look like the code below.

MyDll.h:

MyDll.cpp:

At this point, everything should compile just fine.  I have purposely not changed any project settings yet to enable managed code – but don’t worry, we’ll get to that!  Let’s make sure we can actually use and call this dll from the test program first.

7.

Change the default calling convention for the MyDll project to __stdcall.  You do this by right clicking on the project in the Solution Explorer and selecting “Properties…”.  Change the “Configuration” option to “All Configurations” and then select “C/C++ -> Advanced”.  Change the “Calling Convention” entry in the property page to “__stdcall (/Gz)” and select OK.

I’m not sure this step is actually necessary, but __stdcall is the same calling convention used by the Windows API and will make your dll easily callable from languages such as Visual Basic 6 that can’t handle the default __cdecl calling convention.

8.

Add a module definition file to the MyDll project – this will allow us to override the default name mangling done by the compiler, and make the dll more easily callable.  Right click on the MyDll project in the Solution Explorer and select “Add -> New Item…”.

9.

In the “Templates” pane of the “Add New Item” dialog, select “Module-Definition File (.def)”.  Give it a name.  Select the “Add” button.

10.

Edit your module definition file so that it looks like this (it will have a .def extension):

11.

Edit your CallCSharpCodeSample.cpp file to look like this:

At this point, assuming you’ve done everything correctly, you should be able to compile and run the application:

12.

Now that the dll and it’s test harness are in place, let’s return our attention to the MyDll project.  At this step, we are going to enable CLR support.  Right click on the MyDll project in Solution Explorer and select “Properties…”.  Set the “Configuration” option to “All Configurations”.  Select “Configuration Properties -> General” in the menu tree, and then change the “Common Language Runtime support” option in the properties pane to “Common Language Runtime Support (/clr)” and select the “OK” button.

13.

Right click on your MyDll project in the Solution Explorer and select “References…”.  When the “Property Pages” dialog appears, select the “Add New Reference…” button.

In the “Add Reference” dialog, select the “Projects” tab.  Select the CustomCSharpLib project from the list.  Select OK.

This will add the reference to the C# class library to your MyDll project.  Select OK on the “Property Pages” dialog.

14.

Edit MyDll.cpp to look like this:

Then compile and run your project.  If all goes well, this is what you should see: