我的项目因以下消息而崩溃：clang：错误：链接器命令失败，退出代码为 1（使用 -v 查看调用）
我无法弄清楚我做错了什么。我已经删除了所有有问题的代码（我认为），我什至将所有内容都删除回原来的类，但我仍然收到消息。有什么建议么？谢谢。
这是整个日志：
Ld /Users/xxxx/Library/Developer/Xcode/DerivedData/NewTest-gwytsbxrryxjejdbvifxuyomdpug/Build/Products/Debug-iphonesimulator/NewTest.app/NewTest normal i386
cd "/Users/xxxx/Desktop/NewTest copy"
setenv MACOSX_DEPLOYMENT_TARGET 10.6
setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch i386 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.1.sdk -L/Users/xxxx/Library/Developer/Xcode/DerivedData/NewTest-gwytsbxrryxjejdbvifxuyomdpug/Build/Products/Debug-iphonesimulator -F/Users/xxxx/Library/Developer/Xcode/DerivedData/NewTest-gwytsbxrryxjejdbvifxuyomdpug/Build/Products/Debug-iphonesimulator -filelist /Users/xxxx/Library/Developer/Xcode/DerivedData/NewTest-gwytsbxrryxjejdbvifxuyomdpug/Build/Intermediates/NewTest.build/Debug-iphonesimulator/NewTest.build/Objects-normal/i386/NewTest.LinkFileList -mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -fobjc-arc -Xlinker -no_implicit_dylibs -D__IPHONE_OS_VERSION_MIN_REQUIRED=50100 -framework UIKit -framework Foundation -framework CoreGraphics -o /Users/xxxx/Library/Developer/Xcode/DerivedData/NewTest-gwytsbxrryxjejdbvifxuyomdpug/Build/Products/Debug-iphonesimulator/NewTest.app/NewTest
ld: duplicate symbol _OBJC_IVAR_$_ViewController.testprop3 in /Users/xxxx/Library/Developer/Xcode/DerivedData/NewTest-gwytsbxrryxjejdbvifxuyomdpug/Build/Intermediates/NewTest.build/Debug-iphonesimulator/NewTest.build/Objects-normal/i386/OtherClass.o and /Users/xxxx/Library/Developer/Xcode/DerivedData/NewTest-gwytsbxrryxjejdbvifxuyomdpug/Build/Intermediates/NewTest.build/Debug-iphonesimulator/NewTest.build/Objects-normal/i386/ViewController.o for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Duplicate symbol _OBJC_IVAR_$_ViewController.testprop3 in /Users/xxxx/Library/Developer/Xcode/DerivedData/NewTest-gwytsbxrryxjejdbvifxuyomdpug/Build/Intermediates/NewTest.build/Debug-iphonesimulator/NewTest.build/Objects-normal/i386/OtherClass.o and /Users/xxxx/Library/Developer/Xcode/DerivedData/NewTest-gwytsbxrryxjejdbvifxuyomdpug/Build/Intermediates/NewTest.build/Debug-iphonesimulator/NewTest.build/Objects-normal/i386/ViewController.o for architecture i386