iOS工程中用到了百度地图，编译报错！

ndefined symbols for architecture arm64:
"_OBJCCLASS$_BMKLocationServiceWrap", referenced from:
objc-class-ref in libbmapimp.a(pg_map_view.o)
"_OBJCCLASS$_PGBaiduKeyVerify", referenced from:
objc-class-ref in libbmapimp.a(pg_map.o)
objc-class-ref in libbmapimp.a(pg_map_view.o)
"_BMKAreaBetweenCoordinates", referenced from:
-[PGMap calculateArea:] in libbmapimp.a(pg_map.o)
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)