Develop Reference

How to get the base address of a .NET module

I've been doing some testing recently with a C# app. This app uses a load of C# DLLs, and I'm trying to find a way to find the base address of these DLLs. Enumerating through all the modules via functions like EnumProcessModulesEx only shows the windows DLLs, but that's when I discovered through the Windows Resource Monitor that the C# DLLs that I'm looking for can only be found in the 'Associated Handles' section and not the 'Associated Modules' section, so that begs the question. How can you grab the base address of a C# DLL that would appear under the Associated Handles of a process?
NOTE - I know that this is possible to do because apps like Extreme Dumper that specialize in C# applications have the ability to get the base address of these DLLs, but the method that's used in that is way over the top.

Creating .Net Wrappers for Windows API and COM DLLs

Let me start by saying that I don't know what I don't know at this point, so rather than specific answers, I'm also looking for better questions to ask, I think. My .Net/C# is solid enough, and my C/C++ is meh.
Lately, I'm finding that there are no libraries in the standard .Net framework to accomplish certain tasks, and while it's easy enough to download a third party library, I'd like to understand how to do it myself if one doesn't already exist.
In one recent case, I need to deal with MIDI in windows at a relatively low-level, and I accidentally found out that "winmm.dll" is the library I'll need to use by downloading a .net wrapper for MIDI and browsing through the source. I understand that I'll have to make a wrapper class and do the whole P/Invoke thing to make that happen.
The next thing I did was to search for documentation on the Windows API to figure out what was going on in the mystery box of "winmm.dll," and to my delight, there was a whole Windows SDK that I was able to download and read through. I went through the "getting started" section of "Windows Development" which covered some of the basics via C++. It talked a bit about COM, windows header files, and I know enough C++ to get the gist.
Now, I need help connecting the dots on a few issues:
1) The Windows SDK, so far, seems to suggest that I want to program to specific header files rather than the dlls themselves, but the .net wrappers I've found typically point to a specific .dll rather that a header file...
/// <summary>
/// Returns the number of MIDI input devices on this system.
/// </summary>
/// Win32 docs: http://msdn.microsoft.com/en-us/library/ms711608(VS.85).aspx
[DllImport("winmm.dll", SetLastError = true)]
public static extern UInt32 midiInGetNumDevs();
I was under the impression that a header file and DLL needed to be in the same folder, but the windows SDK includes a folder with all the windows header files, and no DLLs (I'm guessing the registry comes into play here for mapping to specific libraries?)? How do those header files eventually get mapped to actual libraries, and why does it seem like I don't even need to deal with header files to create a .Net wrapper?
2) I can't seem to find documentation on winmm.dll, but I have found references to the functions I'll likely need in the "Windows API" list in the Windows SDK, and I'm pretty sure that the code for those functions are in winmm.dll. How do I find the documentation for the specific libraries I'll need to begin creating my wrapper? If I didn't know that I was going to need winmm.dll to access windows MIDI functionality, how could I have figured that out myself?
3) Some DLLs are COM, some are plain windows DLLs, some are .net DLLs... how can I tell the different going forward? It seems that creating wrappers for the former two would require a different approach.
4) There is no page on MSDN for "Winmm.dll" listing all of its API, and I assume there's a good and practical reason for that, but I'm not sure what it is? I'm used to .Net land where I can figure out what a library does and how to use it almost without effort.
Thanks in advance for any insights.

The bible on this is Adam Nathans excellent book '.Net and COM the complete interoperability guide'
Includes PInvoke and several audio-type examples

1) The windows API documentation includes the header, library, and dll file for each method/enum/etc. I just didn't scroll down far enough when I read through to notice this. A header file doesn't necessarily have to be in the same directory as the dll; its contents are simply copy/pasted into the .c file when the program is compiled. The part I was missing here was the linking stage of compilation which I read about here
2) The documentation was there--I just had to look for it a little bit harder.
3) How can I detect the type of a dll? (COM, .NET, WIN32)
4) The api for audio could theoretically span multiple dlls, so the best course of action is to find the API documentation, find the methods you want to wrap, then figure out what dlls those methods are in, and then import each of those DLLs.

C# Vlc.DotNet Libraries - Null reference exception

Recently stumbled upon this post whilst trying to decide on the best way of getting a VLC player into C#.
Does VLC media player have a C# interface?
I downloaded the dll files and imported them into my project, but then realised I had no real idea of how to use them. Has anyone got a Windows Forms example of this code that works? The code have tried is shown below -
Vlc.DotNet.Core.Medias.MediaBase media = new
Vlc.DotNet.Core.Medias.PathMedia(#"C:\Users\...\SampleVideos\Wildlife.wmv");
Vlc.DotNet.Forms.VlcControl vlcControl1 = new Vlc.DotNet.Forms.VlcControl();
vlcControl1.Play(media);
I am also using the code in this link in the main program.cs of my project.
http://vlcdotnet.codeplex.com/wikipage?title=Forms
The current problem I experience is that upon starting the project it throws a NullReferenceException when it gets to ->
vlcControl1.Play(media)
The problem seems to be with the vlcControl but I am unsure why. The documentation seems to rather thin and I couldn't find any working examples on the codeplex site. If anyone has a working forms example or knows what I might have missed please let me know!
Here is the call stack present when the error occurs ->
RTSPViewer_Test.exe!RTSPViewer_Test.Form1.Form1_Load(object sender,
System.EventArgs e) Line 31 + 0xd bytes C#
RTSPViewer_Test.exe!RTSPViewer_Test.Program.Main() Line 30 + 0x1d bytes C#
When debugging it appears that the Media and Medias attribute of the VLC control are both null. When trying to set the Media of the control to the media object created above a
NullReferenceException
Checking the VLC control object Media does indeed equal null, but I am not sure why it hasn't been initialised properly.

I was unable to get the program to work using the latest version of the Vlc.dotnet libraries but instead used the alpha 2 version which was posted by Raj. I used VLC version 1.1.5 with this library to get the basic example to function properly. My end objective was to stream from an rtsp device, however this library does not appear to support this functionality yet.
For anyone looking to use a good C# wrapper for using VLC then this is a great example -
http://www.codeproject.com/Articles/109639/nVLC
Used the library files from VLC 1.1.1 with this project and works fine. Supports pretty much all the features that you would usually use in VLC but gives you much more control over what you use them for.
Many of the issues that arise when using these DLL wrappers arose from incorrect versions of the source DLL files. The VLC libraries are only 32 bit at this time, so you need to make sure to compile using x86 mode otherwise the libvlc.dll will not load properly and the application will crash. Using the above example you must also make sure that the libvlc.dll, libvlccore.dll and the plugins folder are included in the build folder.

Can I use uncompiled C++ code in ASP.NET web application?

I've got a problem which I hope you can help me with.
I created ASP.NET 4.0 web application. I've also got .cpp file generated in some other app. This .cpp file contains functions, which always returns the same number of variables and which always takes the same number of parameters.
What I need to do is being able to use this functions in my web application.
But what is real problem is that I need to be able to replace this functions while running app. What I mean is administrator should be able to login, upload new cpp file, which will replace old functions with new ones. New ones will have the same names, parameters and result number, but will make calculations in a different way.
Is there any way this can be achieved?
Thanks for any help!
MattheW

Precompile the cpp code into dlls and let admin upload dll. Reference dll's from c# app using [DllImport("")] directive.

C++ will need to be compiled in some way or another. You can use a compiled dll written in C++ in your ASP.NET application but the code will still need to be compiled for ASP to be able to use it.
The compiled DLL can then be loaded and unloaded to accommodate changes to the function. You could perhaps even make the ASP.NET server compile the file somehow, but the code still needs to be compileable to a DLL to make it executable.

You need to expose the C++ code via another dll.
The first choice is pinvoke. See:
How to set up a C++ function so that it can be used by p/invoke?
It's also covered here:
http://msdn.microsoft.com/en-us/library/aa446538.aspx
Technically you could also expose via COM or write in managed C++ but those are both overkill if you're just trying to expose a few C++ functions.

Online updating a C# program

Greetings,
I'm sorry if this question has been asked already. I've tried using the search function but couldn't find any answer that suited my situation.
I have a real simple C# form application of only 1 file, a exe.
I distributed this currently by 4shared where people can download it as pleased.
However, every time I make changes to the program people will have to download the new version from 4shared.
Now this isn't a ideal situation and I'm a noob when it comes to creating upgrade but the situation I wish is that the program looks at a website / ftp server where I deploy a new version.
I'm looking for a way inside my program to look at the file on that website / ftp server and decide wether there's a new version available.
If there is a new version available in the website / ftp server I would like for the program to update itself to the newest version.
Hope you guys can help me out with this and I hope I explained my situation enough !

NetSparkle is a nice alternative to click-once with more deployment options. http://netsparkle.codeplex.com/

Have a look at ClickOnce. It will do this for you.

When I'm developing and publishing such applications, I usually do it the following way:
Develop a .NET Windows Forms application
Develop a tiny ASP.NET application with an ASMX web service.
Publish the ASMX web service to my public web site.
Add a WSDL reference for the web service to my Windows Forms application.
Create a setup (I prefer Unicode NSIS over ClickOnce).
The logic I implement in the SOAP web service is basically a single function:
[WebMethod]
public string CheckUpdateAvailable( string currentVersion )
{
...
}
The Windows Forms application calls this method (e.g. from a background thread upon program start), passing its current assembly version as a string to the function.
The WSDL function in turn checks the passed version against the newest setup version (e.g. being stored inside web.config or extracted live from the setup.exe on the server). If a newer version exists, it return a string with the URL to download from; otherwise it returns NULL.
When the caller of the WSDL function gets a non-NULL string, it can show a message to the user, asking whether he wants to download and install the executable and then simply execute the URL (via Process.Start).

WyUpdate is the way to go here. We've been using it for over a year with great results (they have excellent support too).
It actually uses patches to update files so that when a 5MB executable only has a small change, the client only has to download a file in the order of kilobytes.
They supply an automatic update component for either Windows Forms or WPF that looks nice and works great.
You can host the update files on either an FTP server or a normal website without any server-side configuration.
There's plenty more to it, and the best place to start is with their video tutorial of how to set up an update.

Here's an open-source library I wrote to address specific needs we had for WinForms and WPF apps. The general idea is to have the greatest flexibility, at the lowest overhead possible. All you'll have to do is create an update feed and reference the library from your app.
So, integration is super-easy, and the library does pretty much everything for you, including synchronizing operations. It is also highly flexible, and lets you determine what tasks to execute and on what conditions - you set the rules (or use some that are there already). Last by not least is the support for any updates source (web, BitTorrent, etc) and any feed format - whatever is not implemented you can just write for yourself.
Cold updates (requiring an application restart) is also supported, and done automatically unless "hot-swap" is specified for the task.
This all boils down to one DLL, less than 70kb in size.
More details at http://www.code972.com/blog/2010/08/nappupdate-application-auto-update-framework-for-dotnet/
Code is at http://github.com/synhershko/NAppUpdate (Licensed under the Apache 2.0 license)
I plan on extending it more when I'll get some more time, but honestly you should be able to quickly enhance it yourself for whatever it currently doesn't support.