We Keep Coding

Visual Studio : How to manage code shared between projects

This has probably been posted before, but I'm not sure what search terms to look for!
Quick explanation.
I have code that is shared between a few projects. This code is still work-in-progress itself. The issue is that whenever I need to update this code for whatever, I don't want to have to do it 3 times, this will become a nightmare.
Is there a way to add it to a project, without copying it into the project folder?
i.e. I want the shared class to be linked into my 3 projects as
C:\code repository\sharedclass.cs NOT \eachproject\bin\sharedclass.cs
Do I have to create it as it's own library project? It would be much better if the compiler could compile it as 'external' code.
Cheers.

As others have said, you can simply right-click on your solution in the solution explorer, select Add > Existing Project, and browse to the common project's .csproj file, and it will be included in the solution from its original location.
There are two problems with this however, which may or may not be an issue, depending on the size of your team:
The common project will be included in each solution with a relative path to the solution file (i.e.: ...\CommonProject\Common.csproj). This means all developers have to have the same working file structure or they will get errors when they try to open the main project.
In the scenario that the common project is referenced by multiple projects (say two - A and B) and a developer working on project A has to make changes to the common project as part of their task, there is no way for that developer to know if the changes they have made will break project B without them actually checking out project B and compiling it. As more and more projects reference the common project, the risk of this happening increases to the point where it becomes unmanageable.
Again, as others have said, there is no 'correct' way to do this. However, the approach I have taken is as follows:
Use continuous integration such as Cruise Control to manage the building of the projects and put the common project as a standalone project on the server.
Create a directory under your source control to house built common DLLs. Have this directory checked out on your build machine and whenever the common project builds, it copies the output DLL into the DLL folder and commits these changes to source control.
Use environment variables on all developers' machines and the build server to control the location of the common DLL folder and reference the DLLs using that variable rather than the hard-coded path. (i.e.: rather than C:\Source\MyCommonProjectDLLS\Common.dll, use $(MyCommonLocation)\Common.dll with the variable 'MyCommonLocation' set to C:\Source\MyCommonProjectDLLS)
For any project which references the common DLL, set up a CI trigger on the build server for that project to watch the common DLL folder. Whenever changes are committed to it, the build server should then build all consuming projects.
This immediately lets you know if you are committing breaking changes for any other project. The only drawback is that, in this model, consuming projects are forced to take updates to the common DLL as soon as they are made. An alternative is to version the Common DLL from the source control revision when it is built, and place each version in its own sub directory under the common DLL folder. So you would end up with:
Common DLLs
-1.0.0.1234
-1.0.0.1235
-1.0.0.1236
And so on. The advantage of this is that each project can then choose when to take updates to the common DLL by simply referencing the new version of the code. However, it cuts both ways as this can mean that some projects are left with older versions of the common code for longer than they should, which can increase the work involved when the time comes to finally bring in those changes.

Yes.
You can add a project from anywhere on your hard drive to a solution. So put the shared code into a class library and add that to your three projects.

Microsoft has been supporting an open source project which comes built into VS now, its called NuGet, you can output your shared project as a nuget file and consume it in your other projects.
It will actually deploy all the files you specify in the package upon build.
This is how .Net supports dependencies now. You will notice that even things like EF come through NuGet packages. You can even host it for free on places like MyGet.org I use this and it works quite well.
http://nuget.org/

I use git submodules to achieve this.
Create a new git repository for each module (project) that you want to share between solutions. I usually also include unit tests for that project in a separate project but in the same git repository.
Add a submodule to the git repository of the solution that will use the shared code. Adding a submodule creates a link to a specific commit of an external repository. When the code in the submodule is updated you will be able to pull the updates to your parent solution, which is essentially the same as updating the reference to the submodule commit. I find that the process is easier to visualise using an app like SourceTree.
Adding the submodule and pulling the latest commit will create a copy of the shared project inside the parent solution folder. Import the project into the parent Visual Studio solution by right-clicking on the solution and selecting "Add existing project".
Add a reference to the shared project in the other projects that will be using it by right-clicking on the project and selecting "Add Reference" and finding the shared project in the "Solution" tab.
Now that the shared project is included in the solution you will be able to push and pull changes to the submodule and these changes will automatically be incorporated into the solution. You will also be able to see the changes in other git repositories that reference the submodule.

Yes, put the code which need to be shared in a separate class library project, build it and reference the DLL created from this build into your other projects.

It is better to extract common part into a separate project library and add reference of this project to all the solutions/dependent projects.
Otherwise you can Add code/file/item as Link.

Whether or not to include external DLLs in C# project

Our project has a lot of external DLLs, most but not all of which are 3rd party DLLs.
Currently we do not have these DLLs included in our project. They are included in SVN and given a path to our build output directory. So, after building our project the neccessary files are there, because of SVN, but the project itself has no knowledge of them.
My feeling is that we should have a folder under the root of our project named something like Dependancies or ThirdParty with all of the DLLs included there and set their build event to copy to the output directory. They would exist in SVN as well, but in the same structure as the project, not in the build output directory.
The project itself only references one of these DLLs called CommunicationProc.DLL. The CommunicationProc.DLL then references all of the other DLLs. We have numerous DLLs to support different types of radio. So not all DLLs will be used, but any one of them may be used depending on the radio type.
As to whether or not the DLLs should be included in the project we have differing opinions internally, some of the team beleives they should only be in SVN and not part of the project itself.
Of note is that this are not .NET DLLs, most are old C DLLs.
What is the accepted practice? Can someone please provide me with a compelling arguement one way or the other as to whether to include them in the project or just SVN?

Its better to have them in a folder on source control and then copy them over to the debug folder on build event. This way you can manage their versions. If a newer version of some dll comes then you can replace the old one and put some comments with check in. Also if you are working in a team, then instead of copying files from debug folder to each team member, you can let each team member to use the same set of dlls from source control. If you are developing some control and want your customers to use that control then its easier for you to have a set of dependent dlls some where so that you can give those to your customer along with your .Net dlls.
I had the same issue with some un-managed dlls and ended up putting them in a folder so that all the team members have the same version of the dlls. Hope this helps.

I include a project that has no code but contains a folder where all the external assemblies and their dependencies are kepts. For each file set the Build Action to None and Copy to Output as Do Not Copyp. The project then references the binaries from this location. In your other projects, reference this special project. When you build, because the special project is referenced and it references all the needed dependencies, the binaries are copied as needed.
If you do not want a special project, still create the folder in your main project, added the assemblies, set their properties, then reference the assemblies as needed.
This gives you complete control over the versions and output, and more importantly, it is simple.

Project reference path in source control?

during development of our application we use a branching structure and while we are developing another team is using earlier builds of our software to create content with it.
To facilitate easy swapping between builds and teams I was hoping to use empty Hintpaths in the content projects' csproj files so that they can use our GAC installed assemblies to build against and in the meantime add a reference path to the projects for our use during development and test cycles where we don't want any assemblies installed in the GAC.
However, it seems reference paths are not stored in the csproj file and thus don't get sourcecontrolled. Since there will be extensive branching it would be less than ideal to have to set all reference paths again when a developer pulls another branch from sourcecontrol.
I've been searching for a bit now and can't seem to find ways to do this. Anybody know of a way to force the reference path in and out of sourcecontrol?
We're talking Visual Studio 2008 and TFS 2008 here.
Cheers,
Anton.

Ok, I seem to be a little clearer in the head after a good night's sleep, took the logical step, namely investigate where exactly the information was stored and how. It turned out the information was stored in the .user file for the project in the project's folder and as it turens out this file contains mbsuild xml.
I then did what I wanted as follows:
Create the Reference path as I required it to facilitate both scenarios without any work.
Browse to the Project's .user file
Copy the PropertyGroup containing the ReferencePath
Paste the PropertyGroup in all the necessary Projects' .csproj xml.
Reload and build.
Done.

The references are stored in the *.csproj file. The nodes are ItemGroup/Reference...
Thomas

This is pretty simple--we do this in our shop.
First, in the Workspace (using Windows Explorer, browse to the Solution folder), create a folder. We name it "Referenced Assemblies". In here, drop all your DLLs.
Now, in the Solution, add a new folder to match the one created in Windows Explorer. Into that folder, add all the DLLs you just dropped in.
Finally, in each project, set up your references to use the DLLs that were added to the solution.
Now your project references DLLs that are part of the solution, so that when the build runs, it will grab the DLL from Source Control to generate the build.
Also, I'd recommend not using the GAC at all if you can avoid it. In my experience, reference behavior is strange. It seems references go first to the GAC, then to the DLL in the local folder, meaning that if the DLL is updated, the one in the GAC is used instead of the DLL in the local folder (which is likely the updated one).

Copy assembly dependencies from lib folder that uses SVN

I have been investigating the best way to store our solutions in SVN and came up with a structure of:
Libraries
EntLib
DLLs
Global
DLLs
SubSonic
DLLs
Source
sln
Project 1
Project 2
Libraries uses svn:externals to pull down the correct version of the assemblies.
My issue is that "Global" has dependencies on other assemblies. These are included in the Global folder. My question is what is the best process for copying these dependency DLLs to the output folder if they aren't referenced by the projects that use "Global"?
I have tried just referencing the files and setting CopyLocal to True but the dependencies are not being found when running the code.
This then lead me to using MSBuild to copy all of the DLLs in "Libraries" to the projects "output" folder using the Copy task which has the attribute SkipUnchangedFiles, but this relies on file size and timestamp to decide whether the file is newer. This will not work if there is a different version of the file with the same size and older. I don't want to copy all of the files every time a build runs unless I absolutely have to.
Any help/past experiences would be awesome!

My apologies...SkipUnchangedFiles checks that the timestamps are different not that they are newer so this will work in our scenario.

ILMerge Best Practices

Do you use ILMerge? Do you use ILMerge to merge multiple assemblies to ease deployment of dll's? Have you found problems with deployment/versioning in production after ILMerging assemblies together?
I'm looking for some advice in regards to using ILMerge to reduce deployment friction, if that is even possible.

I use ILMerge for almost all of my different applications. I have it integrated right into the release build process so what I end up with is one exe per application with no extra dll's.
You can't ILMerge any C++ assemblies that have native code.
You also can't ILMerge any assemblies that contain XAML for WPF (at least I haven't had any success with that). It complains at runtime that the resources cannot be located.
I did write a wrapper executable for ILMerge where I pass in the startup exe name for the project I want to merge, and an output exe name, and then it reflects the dependent assemblies and calls ILMerge with the appropriate command line parameters. It is much easier now when I add new assemblies to the project, I don't have to remember to update the build script.

Introduction
This post shows how to replace all .exe + .dll files with a single combined .exe. It also keeps the debugging .pdb file intact.
For Console Apps
Here is the basic Post Build String for Visual Studio 2010 SP1, using .NET 4.0. I am building a console .exe with all of the sub-.dll files included in it.
"$(SolutionDir)ILMerge\ILMerge.exe" /out:"$(TargetDir)$(TargetName).all.exe" "$(TargetDir)$(TargetName).exe" "$(TargetDir)*.dll" /target:exe /targetplatform:v4,C:\Windows\Microsoft.NET\Framework64\v4.0.30319 /wildcards
Basic hints
The output is a file "AssemblyName.all.exe" which combines all sub-dlls into one .exe.
Notice the ILMerge\ directory. You need to either copy the ILMerge utility into your solution directory (so you can distribute the source without having to worry about documenting the install of ILMerge), or change the this path to point to where ILMerge.exe resides.
Advanced hints
If you have problems with it not working, turn on Output, and select Show output from: Build. Check the exact command that Visual Studio actually generated, and check for errors.
Sample Build Script
This script replaces all .exe + .dll files with a single combined .exe. It also keeps the debugging .pdb file intact.
To use, paste this into your Post Build step, under the Build Events tab in a C# project, and make sure you adjust the path in the first line to point to ILMerge.exe:
rem Create a single .exe that combines the root .exe and all subassemblies.
"$(SolutionDir)ILMerge\ILMerge.exe" /out:"$(TargetDir)$(TargetName).all.exe" "$(TargetDir)$(TargetName).exe" "$(TargetDir)*.dll" /target:exe /targetplatform:v4,C:\Windows\Microsoft.NET\Framework64\v4.0.30319 /wildcards
rem Remove all subassemblies.
del *.dll
rem Remove all .pdb files (except the new, combined pdb we just created).
ren "$(TargetDir)$(TargetName).all.pdb" "$(TargetName).all.pdb.temp"
del *.pdb
ren "$(TargetDir)$(TargetName).all.pdb.temp" "$(TargetName).all.pdb"
rem Delete the original, non-combined .exe.
del "$(TargetDir)$(TargetName).exe"
rem Rename the combined .exe and .pdb to the original project name we started with.
ren "$(TargetDir)$(TargetName).all.pdb" "$(TargetName).pdb"
ren "$(TargetDir)$(TargetName).all.exe" "$(TargetName).exe"
exit 0

We use ILMerge on the Microsoft application blocks - instead of 12 seperate DLL files, we have a single file that we can upload to our client areas, plus the file system structure is alot neater.
After merging the files, I had to edit the visual studio project list, remove the 12 seperate assmeblies and add the single file as a reference, otherwise it would complain that it couldnt find the specific assembly. Im not too sure how this would work on post deployment though, could be worth giving it a try.

I know this is an old question, but we not only use ILMerge to reduce the number of dependencies but also to internalise the "internal" dependencies (eg automapper, restsharp, etc) that are used by the utility. This means they are completely abstracted away, and the project using the merged utility doesn't need to know about them. This again reduces the required references in the project, and allows it to use / update its own version of the same external library if required.

We use ILMerge on quite a few projects. The Web Service Software Factory, for example produces something like 8 assemblies as its output. We merge all of those DLLs into a single DLL so that the service host will only have to reference one DLL.
It makes life somewhat easier, but it's not a big deal either.

We had the same problem with combining WPF dependencies .... ILMerge doesn't appear to deal with these. Costura.Fody worked perfectly for us however and took about 5 minutes to get going... a very good experience.
Just install with Nuget (selecting the correct default project in the Package Manager Console). It introduces itself into the target project and the default settings worked immediately for us.
It merges the all DLLs marked "Copy Local" = true and produces a merged .EXE (alongside the standard output), which is nicely compressed in size (much less than the total output size).
The license is MIT as so you can modify/distribute as required.
https://github.com/Fody/Costura/

Note that for windows GUI programs (eg WinForms) you'll want to use the /target:winexe switch. The /target:exe switch creates a merged console application.

I'm just starting out using ILMerge as part of my CI build to combine a lot of finely grained WCF contracts into a single library. It works very well, however the new merged lib can't easily co-exist with its component libraries, or other libs that depend on those component libraries.
If, in a new project, you reference both your ILMerged lib and also a legacy library that depends on one of the inputs you gave to ILMerge, you'll find that you can't pass any type from the ILMerged lib to any method in the legacy library without doing some sort of type mapping (e.g. automapper or manual mapping). This is because once everything's compiled, the types are effectively qualified with an assembly name.
The names will also collide but you can fix that using extern alias.
My advice would be to avoid including in your merged assembly any publicly available lib that your merged assembly exposes (e.g. via a return type, method/constructor parameter, field, property, generic...) unless you know for sure that the user of your merged assembly does not and will never depend on the free-standing version of the same library.

We ran into problems when merging DLLs that have resources in the same namespace. In the merging process one of the resource namespaces was renamed and thus the resources couldn't be located. Maybe we're just doing something wrong there, still investigating the issue.

We just started using ILMerge in our solutions that are redistributed and used in our other projects and so far so good. Everything seems to work okay. We even obfuscated the packaged assembly directly.
We are considering doing the same with the MS Enterprise Library assemblies.
The only real issue I see with it is versioning of individual assemblies from the package.

I recently had issue where I had ilmerged assembly in the assembly i had some classes these were being called via reflection in Umbraco opensource CMS.
The information to make the call via reflection was taken from db table that had assembly name and namespace of class that implemented and interface. The issue was that the reflection call would fail when dll was il merged however if dll was separate it all worked fine. I think issue may be similar to the one longeasy is having?

It seems to me like the #1 ILMerge Best Practice is Don't Use ILMerge. Instead, use SmartAssembly. One reason for this is that the #2 ILMerge Best Practice is to always run PEVerify after you do an ILMerge, because ILMerge does not guarantee it will correctly merge assemblies into a valid executable.
Other ILMerge disadvantages:
when merging, it strips XML Comments (if I cared about this, I would use an obfuscation tool)
it doesn't correctly handle creating a corresponding .pdb file
Another tool worth paying attention to is Mono.Cecil and the Mono.Linker [2] tool.
[2]: http:// www.mono-project.com/Linker