常见问题
1.ld: file not found
ld: file not found: /Users/chenweidong/Library/Developer/Xcode/DerivedData/WanHao-bgcnskgmqpeizsfmbpcbxnysukqu/Build/Products/Debug-iphoneos/WanHao.app/WanHao
clang: error: linker command failed with exit code 1 (use -v to see invocation)
解决方案: 修改build setting中的product名字