complex object to ASP.NET WebAPI method

This message is directed to the creators of Ionic.

There seems to be a lot of answers but no real solutions to a problem I am trying to solve. So the problem is:
Please indicate by way of example (ionic 2+) with Typescript how to construct a complex object before sending this object to method.
Also please indicate MIME-TYPE /CONTENT TYPE as well.
If you have the example of the receiving method ASP.NET WepAPI that would be surely welcome.

Thank you.

Also please let me know if this is an Angular 2+ issue instead. I will then post to Angular forum.

It does not seem that this forum is very useful. Has no one had this problem?

Hi Xenc,

Actually, I am using Content-Type: application/json

worked well for post method.

thank you .