Invalid redeclaration of ****

Question

Note: I\'ve search a lot, such as Invalid redeclaration of UITableViewDataSource method? not apply to my case. For there is no duplicate file or class in m

Answer 1

• Go your project root directory->Build phases.
• Under complied resources, check AppDelegate file is added twice or not.

If it is added twice, then added one file.

Answer 2

I add this answer as a supplement of pkc456's answer.

Both redeclaration and recompile can cause the issue.

In my code there is no redeclaration, so it's the recompile cause it.

I go to the Build phases menu, and I found the AppDelegate.swift file added twice there.

Solution:

1. Select either of the two AppDelegate.swift file, and click the - to remove it.

2. Clean and build the project(For Xcode Version 9.3 (9E145) Product->Clean and Product->Build).