Roslyn CodeFix cannot find previously created additional document

Question

I am writing a C # Roslyn and CodeFix parser that will create a new file .txtbased on some variables if it does not exist and it will add a new line if that happens. The analyzer and file creation work fine using the following code in RegisterCodeFixAction:

var proj = document.Project.AddAdditionalDocument("file.txt",
            "text content");
return proj.Solution;

Although, when I try to search the collection of projects AdditionalDocuments, it is empty, even if the file was created earlier (and the project is saved, if that matters).

var doc = document.Project.AdditionalDocuments.FirstOrDefault(x =>
 x.Name == "file.txt"); //doc is null

I tried to add a new file as simple Documentinstead AdditionalDocument, but file.txtcreated as a source code file file.cs, not as .txt, but for some reason, I can find it as file.csin a collection Project.Documents.

, CodeFixProvider ?

Answer 1

workspace :

workspace.TryApplyChanges(proj.Solution);

, , , AddAdditionalDocument() workspace , .

, AddDocument() , , , AddDocument() on #, .cs ", .