How to Retrieving Part of a Document with "SearchCommand"?

[evonneK]

Hello.

I want to use SearchCommand like this

new SearchCommand(string index = "A", string type = "B")

to replace a string command = "http://staging.p2shop.cn:9200/A/B/_search?_source=shopcode".

What should I do to deal with this part(_search?_source=shopcode)?

PS :elastic learn Docs about Retrieving Part of a Document