swift解决present相机导航栏颜色问题

问题1、最近一直在开发swift项目，遇到一个问题，就是我们项目的导航栏文字是白色，当我们present进入相册中时， 会发现相册导航栏的文字颜色也是白色， 无法看到。解决这个问题，只需要我们在加载UIImagePickerController，对相册导航栏进行设置即可：

fileprivate lazy var imagePicker : UIImagePickerController = {
        let imgPicker = UIImagePickerController()
        // 允许编辑
        imgPicker.allowsEditing = true
        // 导航栏字体颜色
        imgPicker.navigationBar.tintColor = UIColor.black
        let dict:NSDictionary = [NSAttributedStringKey.foregroundColor: UIColor.black,NSAttributedStringKey.font : UIFont.boldSystemFont(ofSize: 18)]
        //标题设置颜色与字体大小
        imgPicker.navigationBar.titleTextAttributes = dict as? [NSAttributedStringKey : AnyObject]
        //设置代理，检测操作
        imgPicker.delegate = self as UIImagePickerControllerDelegate & UINavigationControllerDelegate
        return imgPicker
    }()

问题2、解决拍照自动旋转90度问题
OC版本代码：

- (UIImage *)fixOrientation:(UIImage *)aImage {
    // No-op if the orientation is already correct
    if (aImage.imageOrientation == UIImageOrientationUp)
        return aImage;
    
    // We need to calculate the proper transformation to make the image upright.
    // We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
    CGAffineTransform transform = CGAffineTransformIdentity;
    
    switch (aImage.imageOrientation) {
        case UIImageOrientationDown:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;
            
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
            transform = CGAffineTransformRotate(transform, M_PI_2);
            break;
            
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, 0, aImage.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        default:
            break;
    }
    
    switch (aImage.imageOrientation) {
        case UIImageOrientationUpMirrored:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
            
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.height, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
        default:
            break;
    }
    
    // Now we draw the underlying CGImage into a new context, applying the transform
    // calculated above.
    CGContextRef ctx = CGBitmapContextCreate(NULL, aImage.size.width, aImage.size.height,
                                             CGImageGetBitsPerComponent(aImage.CGImage), 0,
                                             CGImageGetColorSpace(aImage.CGImage),
                                             CGImageGetBitmapInfo(aImage.CGImage));
    CGContextConcatCTM(ctx, transform);
    switch (aImage.imageOrientation) {
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            // Grr...
            CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.height,aImage.size.width), aImage.CGImage);
            break;
            
        default:
            CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.width,aImage.size.height), aImage.CGImage);
            break;
    }
    
    // And now we just create a new UIImage from the drawing context
    CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
    UIImage *img = [UIImage imageWithCGImage:cgimg];
    CGContextRelease(ctx);
    CGImageRelease(cgimg);
    return img;
}

Swift版本代码：

/// 解决拍照自动旋转90度问题
    ///
    /// - Parameter aImage: <#aImage description#>
    public final func fixOrientation(aImage: UIImage) -> UIImage {
        // 取向正确，则不操作
        if aImage.imageOrientation == UIImageOrientation.up {
            return aImage
        }
        
        //通过合理的计算使用正确的取向图片
        //我们用2步骤:如果左/右/向下旋转,然后让镜像翻转
        var transform = CGAffineTransform.identity
        
        switch aImage.imageOrientation {
        case .down, .downMirrored:
            transform = transform.translatedBy(x: aImage.size.width, y: aImage.size.height)
            transform = transform.rotated(by: .pi)
        case .left, .leftMirrored:
            transform = transform.translatedBy(x: aImage.size.width, y: 0)
            transform = transform.rotated(by: .pi / 2)
        case .right, .rightMirrored:
            transform = transform.translatedBy(x: 0, y: aImage.size.height)
            transform = transform.rotated(by: -.pi / 2)
        default:break
        }
        
        switch aImage.imageOrientation {
        case .upMirrored, .downMirrored:
            transform = transform.translatedBy(x: aImage.size.width, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        case .leftMirrored, .rightMirrored:
            transform = transform.translatedBy(x: aImage.size.height, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        default:break
        }
        
        let ctx = CGContext(data: nil, width: Int(aImage.size.width), height: Int(aImage.size.height), bitsPerComponent: aImage.cgImage!.bitsPerComponent, bytesPerRow: 0, space: aImage.cgImage!.colorSpace!, bitmapInfo: aImage.cgImage!.bitmapInfo.rawValue)
        ctx?.concatenate(transform)
        
        switch aImage.imageOrientation {
        case .left, .leftMirrored, .right, .rightMirrored:
            ctx?.draw(aImage.cgImage!, in: CGRect(x: CGFloat(0), y: CGFloat(0), width: CGFloat(size.height), height: CGFloat(size.width)))
        default:
            ctx?.draw(aImage.cgImage!, in: CGRect(x: CGFloat(0), y: CGFloat(0), width: CGFloat(size.width), height: CGFloat(size.height)))
        }
        
        let cgimg: CGImage = (ctx?.makeImage())!
        let img = UIImage(cgImage: cgimg)
        
        return img
    }