我正在尝试使用PDColoredProgressView。它之前是可以工作的，但是由于某些原因，XCode现在出现了27个Apple Mach-O链接器（Id）错误。这是怎么回事？有人能解释一下吗？谢谢！
Ld /Users/xxxxxxxx/Library/Developer/Xcode/DerivedData/xxxxx-cqamvgtgfzdealbjtkomtjzxkdgr/Build/Intermediates/xxxxxxx.build/Debug-iphoneos/xxxxx.build/Objects-normal/armv6/xxxxx normal armv6
cd "/Users/xxxxxxx/Documents/iPhone Apps/xxxxx"
setenv IPHONEOS_DEPLOYMENT_TARGET 4.0
setenv PATH "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc-4.2 -arch armv6 -isysroot /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk -L/Users/xxxxxxxxx/Library/Developer/Xcode/DerivedData/xxxxx-cqamvgtgfzdealbjtkomtjzxkdgr/Build/Products/Debug-iphoneos -F/Users/xxxxxxxxx/Library/Developer/Xcode/DerivedData/xxxxx-cqamvgtgfzdealbjtkomtjzxkdgr/Build/Products/Debug-iphoneos -filelist /Users/xxxxxxxxx/Library/Developer/Xcode/DerivedData/xxxxx-cqamvgtgfzdealbjtkomtjzxkdgr/Build/Intermediates/xxxxx.build/Debug-iphoneos/xxxxx.build/Objects-normal/armv6/xxxxx.LinkFileList -dead_strip -miphoneos-version-min=4.0 -framework UIKit -framework Foundation -framework QuartzCore -o /Users/xxxxxxxxx/Library/Developer/Xcode/DerivedData/xxxxx-cqamvgtgfzdealbjtkomtjzxkdgr/Build/Intermediates/xxxxx.build/Debug-iphoneos/xxxxx.build/Objects-normal/armv6/xxxxx
Undefined symbols for architecture armv6:
"_CGRectGetMinX", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGRectGetMinY", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGContextSetRGBStrokeColor", referenced from:
-[PDColoredProgressView drawRect:] in PDColoredProgressView.o
"_CGContextSetLineWidth", referenced from:
-[PDColoredProgressView drawRect:] in PDColoredProgressView.o
"_CGContextIsPathEmpty", referenced from:
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGColorSpaceCreateDeviceRGB", referenced from:
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGContextSaveGState", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGRectGetHeight", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
"_CGContextStrokeRect", referenced from:
-[PDColoredProgressView drawRect:] in PDColoredProgressView.o
"_CGContextRestoreGState", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGContextSetFillColorWithColor", referenced from:
-[PDColoredProgressView drawRect:] in PDColoredProgressView.o
"_CGRectGetWidth", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
"_CGContextTranslateCTM", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGContextScaleCTM", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
"_CGContextSetRGBFillColor", referenced from:
-[PDColoredProgressView drawRect:] in PDColoredProgressView.o
"_CGContextMoveToPoint", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
-[PDColoredProgressView drawRect:] in PDColoredProgressView.o
"_CGContextFillRect", referenced from:
-[PDColoredProgressView drawRect:] in PDColoredProgressView.o
"_CGContextClip", referenced from:
_fillRectWithLinearGradient in PDColoredProgressView.o
-[PDColoredProgressView drawRect:] in PDColoredProgressView.o
"_CGContextAddLineToPoint", referenced from:
-[PDColoredProgressView drawRect:] in PDColoredProgressView.o
"_CGContextStrokePath", referenced from:
-[PDColoredProgressView drawRect:] in PDColoredProgressView.o
"_CGContextAddRect", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
"_CGGradientRelease", referenced from:
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGContextDrawLinearGradient", referenced from:
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGColorSpaceRelease", referenced from:
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGContextAddArcToPoint", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
"_CGGradientCreateWithColorComponents", referenced from:
_fillRectWithLinearGradient in PDColoredProgressView.o
"_CGContextClosePath", referenced from:
_addRoundedRectToPath in PDColoredProgressView.o
ld: symbol(s) not found for architecture armv6
collect2: ld returned 1 exit status
感谢您！ *注意：我从错误消息中删除了我的用户名和应用程序名称，并将它们替换为x。