Visual Studio : How to manage code shared between projects - c#

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.

Related

How to reference a class libraries into other class libraries and web?

In my .net project I have 4 class libraries and a web project. Can you please guide me towards the correct way to add a reference of one class library to another class library?
In every project inside Bin there are two folders:
Debug
Release
I have tried selecting an assembly reference form Bin/Debug/, but every time I clear my project, all references are lost and I have to build projects one by one, which is a sort of pain. Also, it looks like when I build projects in Release mode these references will not work again.
My way of referring is probably not correct. Can you please guide me towards the best way to use references? Is there any way that I can be saved from these issues?
The bin and release folders are there for building the project, thus when cleaning the solution those will be deleted (usually).
We usually add a folder, and place referenced assemblies in this folder, the folder forms part of your main solution structure, so it may be checked into source control.

How to use my DLL when it is not in the GAC

If I have a Project which uses my own made .dll and this .dll is not registered with the GAC but simply in the same folder as my projects App. eg C:\Program Files (x86)\MyApp Folder.
Can I, and more importantly how do I properly reference this .dll if I want to for example build a second project which also uses this .dll. It is possible that I build a few small apps that will use this .dll.
In this case must I have it in the GAC or if it is not there what must I do?
If I have a Project...
You should never put yourself in a situation where you have just a project. You first and foremost have a solution. A collection of projects that, together, build an app. Projects of course have a dependency on each other, you use a project dependency to tell the compiler about. Which automatically takes care of reference assemblies, the output of one project becomes the reference of another. And any changes you make to the source code of such a project automatically propagate to the others.
This is usually as far as teams take it.
This however tends to not work so well on very large solutions with dozens of projects, Visual Studio tends to get sluggish and building can take a long time. An important step to take in such a case is to freeze a root project. A programmer needs to get an explicit permission to make changes to such a core project. Because such a change tends to be very destabilizing, requiring many changes in dependent projects. And effectively destroys many hours of testing and validation time.
You do this by explicitly removing a project from a solution. Which now automatically makes it difficult to make changes to it. The dependent projects need to be updated to use an explicit reference assembly instead of the project dependency. Picking a well-known location for the assembly is important. Either source control or (preferrably) a build server is instrumental to be the source of the assembly. A tool like Nuget can be very useful.

VS2010 generates different assembly each time compiling the project

I have some c# projects. I added post build event to those projects that copy the resulted assembly (dll) from the bin into common folder.
It appears that each compile generates assembly which is binary different from the previous even when I don't modify the project files.
It is quite a problem for me since I'm using Kiln that monitor those file and think they were modified.
I read somewhere that the dll stores time stamp of compilation which if true then I cannot fix this. If so how do you manage your shared DLL in such a way that your repository (Git/HG) doesn't commit all your compiled projects that weren't modified?
Thanks,
Eran.
To address the specific question of "How do you manage your shared DLL in such a way that your repository (Git/HG) doesn't commit all your compiled projects that weren't modified?", I have a very simple answer: ignore.
We exclude /bin and /obj from the directories which our source control will even attempt to commit. This does mean that you will need to recompile the code on each machine after each change, but Visual Studio would do that anyway for any project where the code has changed.
Don't commit the output folders of your projects.
If you want to have a Setup folder or something similar that always contains the latest versions of the assemblies created by your projects, the solution is to make sure that your post-build event is configured to run only when the build updates the project output. There is an option that is named like this:

How do I build a multiple project solution in Visual Studio without dependencies between the binaries?

I'm using Visual Studio 2010 Pro to build a solution that contains two projects. Project A contains most of my source code, while Project B is intended to run independently, but must use some of the source code contained in Project A.
Under the current configuration, Project A is contained as a reference within Project B. I'd like to be able to build and maintain versions of each project independently, but it appears that when I build the entire solution, ProjectB.exe cannot run without ProjectA.exe in the same local directory. I would think and hope that when the .exe binaries are compiled that all of their dependencies are packaged within each, but that appears not to be the case. In fact, any attempt to run ProjectB.exe while ProjectA.exe is not present results in a System.IO.FileNotFoundException.
Is there a way to build a version ProjectB.exe that runs independently and avoids code duplication?
In cases where you want common code, the best solution is to break out the common classes into a third assembly to serve as a library. (As per Adriano's suggestion.) The other option he hints at is to use the "as link" option when using the "add existing file" to the second project.
If you don't know where it is, use the "Add existing file" option, then in the dialog box to select the file, the "Add" button has a drop-down selection where you can select "As Linked File" (or something to that effect.)
This allows you to compile the same classes into multiple projects. But keep in mind that the namespacing for the linked file cannot be changed for the second project. If the namespace was "ProjectA.Domain", this is how you need to access it in Project B. This was a useful trick for Silverlight projects back before the multi-platform assemblies were introduced.
If you want to get rid or the dependency on A, you will have to extract the common logic into another project (let's call it C), as Adriano suggested in a comment.
If you need even looser bond between the projects, you can reference A (or C) not as a project, but as a built assembly (.dll file) and check Specific Version reference property to True. Additionally, if your project/codebase structure is more complex, check more assembly sharing options here.
Some options:
The common option: Separate the common code into a third class library (DLL) project. And have both ProjectA and ProjectB dependent on it. The downside is that now in order to run the projects you need two files (the main exe and the dll.) This method is how most software is developed: a single executable and a bunch of DLLs.
The correct option: Separate the common code into a third project and modify the project files to create executables that contain both assemblies (similar to statically linked libraries in unmanaged code.) The downside is that Visual Studio does not support this out of the box and you need to modify the project files which are actually MS-Build definition files to do this.
The ugly option: Create shortcuts for the common files in ProjectA in ProjectB. This is the same as copying the common code to the other project, but you're still left with one source file. The downside is that you have to do this for every file and maintain the same structure in both projects. This is an ugly, if viable, option. Choose one of the others.

Share Common codes between multiple projects

I have a class library project contains common codes that used in my projects and i use subversion as source control.
i have some question about managing solution,projects and codes for usability.
I want share this class library between projects and when i update it , the update applying easily to all projects.Where can i locate this class library to share between projects and improve source controlling , usability and ...?
Any Idea?
You can use NuGet packages as a means of distributing the DLLs - build your common assemblies, pack build results into a specific directory and use that directory as a repository for NuGet Package Manager. One part of NuGet options is downloading the latest package version automatically, so whenever you open the solution, the package manager scans the repository for newer version and downloads it, if there is one.
Here's a very easy tutorial: http://juristr.com/blog/2012/04/using-nuget-to-distribute-our-company/
You can use several approaches:
You can add this project as existing project to all solutions from one place. It is simplest method, but when it is changed in one solution, all other can become broken.
You can branch your common library project to all solutions as different brunch. In this case, when you change it in one solution, all other solutions will not brake, but you should spend much time to merge changes from all brunches of your common library.
A solution can contain many projects, so you can effectively put the class library project anywhere and reference it from each new solution as required. This means you have only one copy of the source on your machine.
When you build each project it will compile the class library if necessary so all you need to do is have some process that keeps the source up to date.

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