http://stackoverflow.com/questions/15057273/duplicate-symbols-for-architecture-i386-and-couldnt-find-same-name-of-class-and
解决：
Go to Project Target-> Build Phases->Look for multiple occurrences of same file under "Compile Sources".
You can search for file name there as well.
Remove multiple occurrences from there.
中一个即可
duplicate symbols for architecture i386 问题？
原文：http://www.cnblogs.com/wuwangchuxin/p/3986237.html