P/Invoke Library - VS2005 & 2008 Add-in

• Download binaries - 65.3 KB
• Download source - 154 KB
• Download setup - 545 KB

Introduction

This article describes the PInvokeLib Visual Studio Add-in. This tool will help you organize P/Invoke signatures that you use regularly in your application. Hopefully, you will not find this tool outdated since it provides several features not found in other tools.

Background

One website that I visit regularly is pInvoke.net. This is a pretty cool website with a web service back-end. Similarly, it provides a Visual Studio add-in to communicate with their service and let you insert P/Invoke signatures in your program. I'm sure this website will continue to serve the .NET community for years to come. PInvokeLib is intended to complement such a tool by letting you organize your own library as well. In fact, you can almost cut and paste functions from the MSDN or your own header files. Only minor modifications may be required. PInvokeLib supports the following programming languages: C#, VB .NET, and MC++.

Getting Started

The PInvokeLib Manager has two tabs. The Module tab is where you can insert P/Invoke signatures. Currently, only functions and structures can be added. Use the Define tab to define your functions and structures. You can Add, Update, Delete, and Search a definition. Search is limited to selected modules only. Search can also use the wildcard character (*).

Inserting an API Function

• Select or add a module name
• Type the function name
• Type or paste in the function prototype (simply remove the extra semi-colon (;))
• Click the 'Update' button to add your library

Note: Most C types are already defined, and can be reused as is. C pointers other than character strings are not supported.

PInvokeLib will convert any unknown types to uppercase, and make them easier to find. I believe this will make life easier for you, in case you need to define your own struct later.

Inserting a Structure

• Select or add a module name
• Type the structure name
• Type or paste in the structure definition

Advanced Features

Function argument direction support P/Invoke signatures can be specified to have function arguments passed by value (default), by reference, or output only. This is supported only for function prototypes.

PInvokeLib supports the following extensions for parameters:

• [In] - This specifies that the input parameter is being passed by value (this is default if none is present).
• [Out] - This specifies that the output parameter is used.
• [In,Out] - This specifies in/out parameter.

For example, let's import LPWSTR PathAddBackslashW( LPWSTR lpszPath) of the ShlwApi.dll. To do so, the correct definition would be: LPWSTR PathAddBackslashW( [In,Out] LPWSTR lpszPath) since the string argument is passed by reference. PInvokeLib suggests:

[DllImport("ShlwAPI.dll")]
public static extern String PathAddBackslashW([In,Out]String lpszPath)

But, for you to get correct results, the input parameter should be a StringBuilder. The following is a full example code using this function:

using System;
using System.IO;
using System.Text;
using System.Runtime.InteropServices;

namespace PInvokeLib
{
    class PInvoke
    {
        [DllImport("ShlwAPI.dll")]
        public static extern String PathAddBackslashW([In,Out]StringBuilder lpszPath);

        public static void Main(string[] args)
        {
           StringBuilder sb = new StringBuilder(@"c:\temp\temp", 200);
           PathAddBackslashW(sb);
           Console.WriteLine("Path with extra slash:"+ sb);
        }
    }
}

Installation

The PInvokeLib add-in is fully supported by Visual Studio 2005 and 2008. Extract all the files in PInvokeAddin_Bin.zip to:

• Visual Studio 2005: <drive:>\Documents and Settings\<username>\My Documents\Visual Studio 2005\Addins
• Visual Studio 2008: <drive:>\Documents and Settings\<username>\My Documents\Visual Studio 2008\Addins

Then, make sure you enable the add-in from the Add-in Manager (Tools->Add-in Manager...). Start the add-in from the context menu (right click in the text editor).

History

Last Updated [02/26/08]

This update will accept #defines (integer). You can barely copy and paste the full header file. See TestFile.h for all support features. You may use C or C++ style comments to remove lines that are causing problems. You may use the proper signature __cdecl or __stdcall to import your function.

The SpecImporter class library is available - a parser class based on CocoR. Feel free to reuse this library in your own program.

As always, enjoy!