问题
As written in this question:
Can I access the MsBuildWorkspace from within a MsBuild Task class?
You cannot use MSBuildWorkspace from an MSBuild task for the same project. However, the only 2 other options are VisualStudioWorkspace and AdhocWorkspace.
Does this mean that there's no option for loading a project from an MSBuild task?
回答1:
You can create a Project from a set command line arguments using CommandLineProject.CreateProjectInfo, so if you have the csc command line, you can use that.
回答2:
I just found the solution in this post: Roslyn: workspace loads in console application but not in msbuild task
It still feels as a workaround, however it's working. There's actually a benefit to it in that the project doesn't have to be compiled anymore in order to load the project!
来源：https://stackoverflow.com/questions/31084013/roslyn-how-to-load-an-existing-project-outside-of-visual-studio