objective-c - iPhone重复符号错误

Question

我有 iPhone 应用程序，我想在其中包含MobFox广告，在我添加他们的框架后，我收到了这个错误：

duplicate symbol _OBJC_CLASS_$_CDataScanner in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CDataScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_CLASS_$_CJSONDeserializer in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONDeserializer.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_CLASS_$_CJSONScanner in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_CLASS_$_CJSONSerializer in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONSerializer.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_IVAR_$_CDataScanner.current in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CDataScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_IVAR_$_CDataScanner.data in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CDataScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_IVAR_$_CDataScanner.end in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CDataScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_IVAR_$_CDataScanner.length in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CDataScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_IVAR_$_CDataScanner.start in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CDataScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_IVAR_$_CJSONDeserializer.scanner in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONDeserializer.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_IVAR_$_CJSONScanner.nullObject in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_IVAR_$_CJSONScanner.strictEscapeCodes in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_METACLASS_$_CDataScanner in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CDataScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_METACLASS_$_CJSONDeserializer in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONDeserializer.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_METACLASS_$_CJSONScanner in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _OBJC_METACLASS_$_CJSONSerializer in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONSerializer.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _kJSONDeserializerErrorDomain in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONDeserializer.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)
duplicate symbol _kJSONScannerErrorDomain in:
    /Users/user/Library/Developer/Xcode/DerivedData/myapp-evegwvxyndhicigkgkdhjdmnybwq/Build/Intermediates/myapp.build/Debug-iphoneos/myapp.build/Objects-normal/armv7/CJSONScanner.o
    /Users/user/Desktop/myapp/MobFox.framework/MobFox(MobFox)

知道为什么会这样吗？我认为这是因为我的应用程序和 mobfox 都使用了这个 json 框架。可以禁用他们的代码吗？