Projects and Solutions in .Net (.csproj and .sln)

Holistic approach or high level approach are common phrases you will hear when beginning the design of a new system or the start of a new project that will modify or enhance an existing program. Therefore, when you begin a new project, start from the solution context. This means, know what the program does end-to-end before you design the changes or enhancements to existing functionality or adding new features to the program.

Visual Studio helps guide us in this approach by giving us both the project and solution grouping classifications. You can think of a solution as everything your program does, while a project is a subset of functionality that contributes to the solution. In larger, enterprise types of programs, you will have many projects that make up a solution. In smaller programs, you may have only a single project for your solution.

Logical naming and grouping of the widows directory paths and namespaces are crucial. Therefore, good design of your application structure goes a long way in supporting the below.

  • Ease of modification and enhancements
  • Source Control Integration
  • Building and distributing your solution
  • Ease of maintenance

I can think of 2 ways to implement. A key question you need to answer is, how many DLL’s do you want or will you need now and in the future? Each project that you create within the solution will result in a DLL that will need to be distributed along with the program. As well, if there are interdependencies between the projects, which is common, you may have to re-compile a project to create a compatible DLL and deploy it along with a new version, even if it did not change.

Adding multiple projects to a solution could be like this structure in Visual Studio and in Windows Explorer.


When you deployed this program you would need to deploy 4 files:

  • CompanyName.SolutionName.exe
  • CompanyName.SolutionName.Project1.dll
  • CompanyName.SolutionName.Project2.dll
  • CompanyName.SolutionName.Project3.dll

The above would be a good approach if you have a large system, or plan to have a large system at some point.

Another approach could be to add sub-directories to a single project within your solution. Doing this may result in this structure in Visual Studio and in Windows Explorer.


When you deployed this program you would need to deploy only the EXE that is created. Everything within the CompanyName.SolutionName project is compiled into a single file.

  • CompanyName.SolutionName.exe

Good design of your projects layout is very important and plays a significant role in the maintenance, enhancement and overall success of your project. Take some time and find which approach is best for you given requirements. Perhaps either of the above will work for you, but you may find a better solution. Let me know if you do.

Leave a Comment

Your email address will not be published.