问题
[EDIT] I was hoping that Apple would have fixed what is obviously a bug. The solution is to clear the cache, close and reopen Xcode..
I am on Xcode Beta and starting a new project and without writing a single line of code I already get an error. I could not find anything online. Perhaps is this too new?
In the new version of Xcode I selected new Project,
then ticked the box with Core Data
If I do not tick the box I would get the usual Xcode SwiftUI template with "hello world", but ticking the Core Data box I get a ton more template code from Apple and without touching anything and without changing a single line of code, I get an error message compiling it..
The error is: "Cannot find Item in scope"
Quite frustrating, especially because all tutorials I have start with the classic 'AppDelegate' file configuration.. while the new SwiftUI is 'universal'!
I checked the file .xcdatamodeld and it looks fine, and has the 'Item' entity. Why it doesn't compile?
So I am now at a loss, is there a solution or this is a bug and need to wait that Apple releases a fix. If so I do not need to start with a new project until then!
PS Today I cleaned the cache with CMD-ALT-SHIFT-K, closed Xcode, deleted the app from the simulator, reopened, rebuilt and it did compile.. but nothing in the simulator! We are making progress! Still I did not change a line of code. Everything is the Apple template yet!
回答1:
The normal Xcode clearing works for me:
- Clean build folder (shift + command + k)
- Close Xcode completely
- Delete 'DerivedData' content (/Library/Developer/Xcode/DerivedData)
- Try again (run Xcode & build)
回答2:
For a brand new project, press Command+B to build and it will be fine.
回答3:
I didn't find any of the others answers worked for me, but what did was:
- Opening (ProjectName).xcdatamodel
- Adding an attribute to the Item entity, shouldn't relly matter what, I just add "foo" of type "String"
- Cmd-B to build (You are then free to delete the new attribute).
来源：https://stackoverflow.com/questions/63603754/swiftui-2-0-coredata-issues-with-new-project-cannot-find-type-item-in-scope