duplicate symbol OBJC_CLASS_Register1ViewController in:
/Users/nb/Library/Developer/Xcode/DerivedData/lottery-dysorfsvdnhspoaasloexqipojof/Build/Intermediates.noindex/lottery.build/Debug-iphoneos/lottery.build/Objects-normal/arm64/LoginViewController.o
/Users/nb/Library/Developer/Xcode/DerivedData/lottery-dysorfsvdnhspoaasloexqipojof/Build/Intermediates.noindex/lottery.build/Debug-iphoneos/lottery.build/Objects-normal/arm64/Register1ViewController.o
ld: 2 duplicate symbols for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

这种错误是import 了.m文件

Xcode中类文件后面的M，A，？等符号，Xcode使用Git的符号表示的意思
https://blog.csdn.net/coco__d/article/details/52763861