Solve the Xcode not insert new outlet connection" problem in

Today when using Xib Association class appears the question, in any case can not related to success, there are several use Baidu Search solution, test a little, hereby record
a simple method directly

Solve the Xcode not insert new outlet connection" problem in
problem description

Solution:
(1) Xcode (2)
close to the ~/Library/Developer/XCode/DerivedData directory, find the link named project with your project name and a string of letters, delete this folder.
(3) re open Xcode