File upload with ASP.Net Core 2.0 Web API and React.js

I’m new to both react.js and ASP.Net core 2.0. And now writing a project using ASP.Net core 2.0 as back end API and react.js as application interface (front end). I’d like to know how to upload file. I have tried as follow but in the Back end side the parameter value (IFromFile file) is always null. And it seems that file was not posted correctly. Here are my codes:

Can the new csproj file structure be used with a ASP.NET Framework project?

The new .csproj format includes some significant improvements over the classic files, including tight integration with NuGet package management and significantly less-verbose structure. I want to gain these benefits whilst still using the .NET Framework 4.6 and ASP.NET (because my project depends on Umbraco which has yet to produce a .NET Core version).