With Visual Studio 2017, you can open code from nearly any type of directory-based project into Visual Studio without the need for a solution or project file. This means you can, for example, find a code project on Git, clone it, and then open it directly into Visual Studio and begin developing without having to create a solution or projects. Not only can you edit the code and build it in Visual Studio, you can also navigate through your code (such as by using the Navigate To command). Code will appear with syntax colorization and, in many cases, include basic statement completion and debugging, complete with breakpoints.
For more info, you can refer the related documentation: https://docs.microsoft.com/en-us/visualstudio/ide/develop-code-in-visual-studio-without-projects-or-solutions
In addition, you can have a look at the following video as well: