iphone - 屏幕截图显示设备中的黑色图像 - cocos2d-iPhone

Question

下面的代码在我的游戏中生成屏幕截图，在模拟器中运行良好，但是当我签入设备时，它显示黑色图像。这是我生成屏幕截图的代码。

CCDirector *director = (CCDirector *) [CCDirector sharedDirector];
screenshootimage = [director screenshotUIImage];
appDelegate.screenshootimage = [Utility getImageFromView];
imgsprite = [CCSprite spriteWithCGImage:screenshootimage.CGImage key:@"s"];

 - (UIImage*) screenshotUIImage
  {
    CGSize displaySize  = [self displaySizeInPixels];
    CGSize winSize      = [self winSizeInPixels];

    //Create buffer for pixels
    GLuint bufferLength = displaySize.width * displaySize.height * 4;
    GLubyte* buffer = (GLubyte*)malloc(bufferLength);

    //Read Pixels from OpenGL
    glReadPixels(0, 0, displaySize.width, displaySize.height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
    //Make data provider with data.
    CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, buffer, bufferLength, NULL);

    //Configure image
    int bitsPerComponent = 8;
    int bitsPerPixel = 32;
    int bytesPerRow = 4 * displaySize.width;
    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
    CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
    CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
    CGImageRef iref = CGImageCreate(displaySize.width, displaySize.height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);

    uint32_t* pixels = (uint32_t*)malloc(bufferLength);
    CGContextRef context = CGBitmapContextCreate(pixels, winSize.width, winSize.height, 8, winSize.width * 4, CGImageGetColorSpace(iref), kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);

    CGContextTranslateCTM(context, 0, displaySize.height);
    CGContextScaleCTM(context, 1.0f, -1.0f);

    switch (deviceOrientation_)
    {
        case CCDeviceOrientationPortrait: break;
        case CCDeviceOrientationPortraitUpsideDown:
            CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(180));
            CGContextTranslateCTM(context, -displaySize.width, -displaySize.height);
            break;
        case CCDeviceOrientationLandscapeLeft:
            CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(-90));
            CGContextTranslateCTM(context, -displaySize.height, 0);
            break;

        case CCDeviceOrientationLandscapeRight:
            CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(90));
            CGContextTranslateCTM(context, displaySize.height-displaySize.width, -displaySize.height);
            break;
    }

    CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, displaySize.width, displaySize.height), iref);
    CGImageRef imageRef = CGBitmapContextCreateImage(context);
    UIImage *outputImage = [[[UIImage alloc] initWithCGImage:imageRef] autorelease];

    //Dealloc
    CGImageRelease(imageRef);
    CGDataProviderRelease(provider);
    CGImageRelease(iref);
    CGColorSpaceRelease(colorSpaceRef);
    CGContextRelease(context);
    free(buffer);
    free(pixels);

    return outputImage;
}

+ (UIImage*)getImageFromView
{
    // Create a graphics context with the target size
    // On iOS 4 and later, use UIGraphicsBeginImageContextWithOptions to take the scale into consideration
    // On iOS prior to 4, fall back to use UIGraphicsBeginImageContext
    //CGSize imageSize = [[UIScreen mainScreen] bounds].size;

    CGSize newImageSize = [[UIScreen mainScreen] bounds].size;
    CGSize imageSize = CGSizeMake(newImageSize.height, newImageSize.width);

    if (NULL != UIGraphicsBeginImageContextWithOptions)
        UIGraphicsBeginImageContextWithOptions(imageSize, NO,1.0);
    else
        UIGraphicsBeginImageContext(imageSize);

    CGContextRef context = UIGraphicsGetCurrentContext();

    // Iterate over every window from back to front
    for (UIWindow *window in [[UIApplication sharedApplication] windows]) 
    {
        if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen])
        {
            // -renderInContext: renders in the coordinate space of the layer,
            // so we must first apply the layer's geometry to the graphics context
            CGContextSaveGState(context);
            // Center the context around the window's anchor point
            CGContextTranslateCTM(context, [window center].y, [window center].x);
            CGContextRotateCTM( context, degreesToRadian( -90 ) ) ;
            // Apply the window's transform about the anchor point
            CGContextConcatCTM(context, [window transform]);

            // Offset by the portion of the bounds left of and above the anchor point
            CGContextTranslateCTM(context,
                                  -imageSize.height *[[window layer] anchorPoint].y,
                                  -imageSize.width *[[window layer] anchorPoint].x);

            // Render the layer hierarchy to the current context
            [[window layer] renderInContext:context];

            // Restore the context
            CGContextRestoreGState(context);
        }
    }

    // Retrieve the screenshot image
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return image;
}

有什么帮助吗？！

注意：它在iPad设备中也可以正常工作，唯一的问题是 iPhone 设备。