為什么在安裝iPhone應用程序時出現CGContext錯誤？

Question

為什么在嘗試安裝iPhone應用程序時出現以下錯誤？

warning: Unable to read symbols for /Library/MobileSubstrate/MobileSubstrate.dylib (file not found).
warning: Unable to read symbols for /Library/Frameworks/CydiaSubstrate.framework/Libraries/SubstrateLoader.dylib (file not found).
2011-02-18 21:57:05.038 Catalog Dev[399:307] MS:Notice: Installing: com.yourcompany.Catalog-Dev [Catalog Dev] (550.32)
2011-02-18 21:57:05.210 Catalog Dev[399:307] MS:Notice: Loading: /Library/MobileSubstrate/DynamicLibraries/Activator.dylib
warning: Unable to read symbols for /Library/MobileSubstrate/DynamicLibraries/Activator.dylib (file not found).
2011-02-18 21:57:05.518 Catalog Dev[399:307] MS:Notice: Loading: /Library/MobileSubstrate/DynamicLibraries/sandcastleclient.dylib
warning: Unable to read symbols for /Library/MobileSubstrate/DynamicLibraries/sandcastleclient.dylib (file not found).
warning: Unable to read symbols for /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.0.2/Symbols/usr/lib/libsubstrate.dylib (file not found).
Fri Feb 18 21:57:11 Moes-iPhone Catalog Dev[399] <Error>: CGContextDrawImage: invalid context 0x0
Fri Feb 18 21:57:11 Moes-iPhone Catalog Dev[399] <Error>: CGContextSetStrokeColorWithColor: invalid context 0x0
Fri Feb 18 21:57:11 Moes-iPhone Catalog Dev[399] <Error>: CGContextSetLineWidth: invalid context 0x0
Fri Feb 18 21:57:11 Moes-iPhone Catalog Dev[399] <Error>: CGContextMoveToPoint: invalid context 0x0
Fri Feb 18 21:57:11 Moes-iPhone Catalog Dev[399] <Error>: CGContextAddLineToPoint: invalid context 0x0
Fri Feb 18 21:57:11 Moes-iPhone Catalog Dev[399] <Error>: CGContextAddLineToPoint: invalid context 0x0
Fri Feb 18 21:57:11 Moes-iPhone Catalog Dev[399] <Error>: CGContextAddLineToPoint: invalid context 0x0
Fri Feb 18 21:57:11 Moes-iPhone Catalog Dev[399] <Error>: CGContextAddLineToPoint: invalid context 0x0
Fri Feb 18 21:57:11 Moes-iPhone Catalog Dev[399] <Error>: CGContextDrawPath: invalid context 0x0
Fri Feb 18 21:57:11 Moes-iPhone Catalog Dev[399] <Error>: CGBitmapContextCreateImage: invalid context 0x0

Answer 1

如果創建的應用程序使用第三方框架（例如，CydiaSubstrate.framework），則必須將該框架復制到應用程序包內的Frameworks文件夾中。

在這里可以找到有關在Xcode中自動執行此過程的出色教程。

更新：

<Error>: CGContextDrawImage: invalid context 0x0 

此錯誤表明您已調用CGContextDrawImage ，但未指定有效的CGContextRef參數。 在沒有看到相關代碼的情況下，我不得不猜測正在發生什么。 CGContextDrawImage的原型如下：

void CGContextDrawImage (
    CGContextRef c,
    CGRect rect,
    CGImageRef image
);

第一個參數必須是有效的圖形上下文 ，通常是當前的圖形上下文，可通過以下方式訪問：

CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];
...
CGContextDrawImage(myContext, someRect, someImage);

Answer 2

似乎您要安裝的應用程序的部署目標比iPhone os版本大。 Xcode抱怨說他弄亂了您的代碼試圖使用的文字符號。