error: linker command failed with exit code 1 (use -v to see invocation)错误解决方法

/Users/pp/Library/Developer/Xcode/DerivedData/Gift-fwctsvvhwsrojcbibvabpdlxpbhm/Build/Intermediates/Gift.build/Debug-iphonesimulator/Gift.build/Objects-normal/x86_64/LHHotViewController.o
    /Users/pp/Library/Developer/Xcode/DerivedData/Gift-fwctsvvhwsrojcbibvabpdlxpbhm/Build/Intermediates/Gift.build/Debug-iphonesimulator/Gift.build/Objects-normal/x86_64/LHFirPageViewController.o
ld: 15 duplicate symbols for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

解决方法:1 .某个文件多次的错误；检查文件是否重复引用； 

              2 也有可能你删除了某个.m文件，引用引起的错误。你可以查看 building phases > compile sources中删除已经不存在的类;