创建映像出的IOS表面并保存(Creating an image out of the ios su

我试图获取与iOS设备的主屏幕相关的面，出它创建一个图像并保存。这是相关性，这个问题- 以从iOS应用程序截图-模拟显示记录（在内部查询）。
代码如下：

    IOMobileFramebufferConnection connect;
    kern_return_t result;

    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, &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 = 4*width*height;
    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);

    CFDictionaryRef ed = (__bridge CFDictionaryRef)[NSDictionary dictionaryWithObjectsAndKeys: nil];
    IOSurfaceAcceleratorTransferSurface(outAcc, screenSurface, destSurf, ed, NULL);

    IOSurfaceUnlock(screenSurface, kIOSurfaceLockReadOnly, &aseed);

    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 *image = [UIImage imageWithCGImage: cgImage];
    CGImageRelease(cgImage);
    UIImageWriteToSavedPhotosAlbum(image, self, nil, nil);

但我得到的是保存在我的照片文件夹中的空白图像。请我要去哪个部分错误的帮助。谢谢。

Answer 1:

我记得我看到了一些关于这个问题（截屏背景）前一段时间。我没能找到我所看见的确切地点和代码。这是我为自己留下唯一要注意的是createScreenIOSurface的使用

我GOOGLE了一点点，发现几个提到：

获取的截图，而应用程序是在后台？（私有的API允许）

https://github.com/rpetrich/FastBlurredNotificationCenter/blob/master/Tweak.x

http://pastie.org/pastes/3734430

我记得代码是方式更紧凑，你表现又是什么。

Answer 2:

如果你在后台运行指定的代码工作。它确实需要的最上表面的屏幕截图iOS设备的显示器上。
面临的问题是由于一个事实，即在应用程序中，它正在采取的应用程序创建的空白视图的屏幕截图。
但是，你必须采取的截图在2秒的最小间隔，否则OS暂停您的应用程序。关于如何提高任何建议将是有益的。