解决方法:打开Build Settings 搜索 Apple LLVM 9.0 - Language - Objective C -------> Weak References in Manual Retain Release 将 No 改成 Yes!

解决方法:打开Build Settings 搜索 Apple LLVM 9.0 - Language - Objective C -------> Weak References in Manual Retain Release 将 No 改成 Yes!