在iOS7中使用IOSurface在游戏中截屏

我试图从背景使用IOSurface截图，这是我的代码

IOMobileFramebufferConnection connect; kern_return_t result; IOSurfaceRef screenSurface = NULL; io_service_t framebufferService = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleH1CLCD")); if(!framebufferService) framebufferService = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleM2CLCD")); if(!framebufferService) framebufferService = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleCLCD")); result = IOMobileFramebufferOpen(framebufferService, mach_task_self(), 0, &connect); result = IOMobileFramebufferGetLayerDefaultSurface(connect, 0, (CoreSurfaceBufferRef*)&screenSurface); uint32_t aseed; IOSurfaceLock(screenSurface, kIOSurfaceLockReadOnly, &aseed); uint32_t width = IOSurfaceGetWidth(screenSurface); uint32_t height = IOSurfaceGetHeight(screenSurface); CFMutableDictionaryRef dict; int pitch = width*4, size = width*height*4; int bPE=4; char pixelFormat[4] = {'A','R','G','B'}; dict = CFDictionaryCreateMutable(kCFAllocatorDefault, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); CFDictionarySetValue(dict, kIOSurfaceIsGlobal, kCFBooleanTrue); CFDictionarySetValue(dict, kIOSurfaceBytesPerRow, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &pitch)); CFDictionarySetValue(dict, kIOSurfaceBytesPerElement, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &bPE)); CFDictionarySetValue(dict, kIOSurfaceWidth, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &width)); CFDictionarySetValue(dict, kIOSurfaceHeight, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &height)); CFDictionarySetValue(dict, kIOSurfacePixelFormat, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, pixelFormat)); CFDictionarySetValue(dict, kIOSurfaceAllocSize, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &size)); IOSurfaceRef destSurf = IOSurfaceCreate(dict); IOSurfaceAcceleratorRef outAcc; IOSurfaceAcceleratorCreate(NULL, 0, &outAcc); IOSurfaceAcceleratorTransferSurface(outAcc, screenSurface, destSurf, dict, NULL); IOSurfaceUnlock(screenSurface, kIOSurfaceLockReadOnly, &aseed); CFRelease(outAcc); CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, IOSurfaceGetBaseAddress(destSurf), (width * height * 4), NULL); CGImageRef cgImage=CGImageCreate(width, height, 8, 8*4, IOSurfaceGetBytesPerRow(destSurf), CGColorSpaceCreateDeviceRGB(), kCGImageAlphaNoneSkipFirst |kCGBitmapByteOrder32Little, provider, NULL, YES, kCGRenderingIntentDefault); UIImage *img = [UIImage imageWithCGImage:cgImage]; saveImage(img); 

我将IOSurface – IOS Private API中的代码- 后台捕获屏幕截图和IOSurfaces – video中的人工影像代码结合在一起，无法轻松修改video表面 ，代码在主屏幕和大多数应用程序中运行良好，但在游戏中返回黑屏。 任何想法如何解决？ 谢谢。