I need to use a namespace called [system.windows.forms][1] in my C# file, while it tells me that "forms" does not exist in bla bla. I looked it up and found that it needs to be added from the solution explorer, by"right click reference". However I don't know what how the solution explorer in my VS only shows a group of "assembly" instead of the program, and there is nowhere to right click "reference". I'm pretty new to VS, please some one tell me what's going on here?
it looks like this: [1]: https://i.stack.imgur.com/ZRfih.png
I'm using VS2019. Thank you all.