vscode Multiple projects set up Referencing local projects

Example

There is no such things as .sln and .proj files.
Instead of them folders are being used in Visual Studio Code.
Each project folder should have a seperate project.json file.

/MyProject.Core
   SourceFile.cs
   project.json

/MyProject.Web
   /Controllers
   /Views
   project.json

To reference MyProject.Core from MyProject.Web project edit MyProject.Web\project.json file and add the dependency:

// MyProject.Web/project.json
{
   "dependencies": {
      "MyProject.Core": {"target": "project"},
    ...
   }
   "buildOptions": {
      "emitEntryPoint": true 
   }
}

The line "emitEntryPoint": true says that MyProject.Web is a start project for the solution. MyProject.Core should have this flag disabled in its project.json file:

 // MyProject.Core/project.json
 {
   ...
   "buildOptions": {
      "emitEntryPoint": false 
   }
}

Build the project (Mac: ⌘+Shift+B, Windows: Ctrl+Shift+B) and each project should have own \bin and \obj folders with new .dll files.