问使用UIGraphicsImageRenderer旋转图像？

EN

extension UIImage
{
    public func rotate(angle:CGFloat)->UIImage
    {
        let radians = CGFloat(angle * .pi) / 180.0 as CGFloat
        
        var newSize = CGRect(origin: CGPoint.zero, size: self.size).applying(CGAffineTransform(rotationAngle: radians)).size
        
        // Trim off the extremely small float value to prevent core graphics from rounding it up
        newSize.width = floor(newSize.width)
        newSize.height = floor(newSize.height)
        let renderer = UIGraphicsImageRenderer(size:newSize)
        
        let image = renderer.image
        { rendederContext in
            
            let context = rendederContext.cgContext
            //rotate from center
            context.translateBy(x: newSize.width/2, y: newSize.height/2)
            context.rotate(by: radians)
            draw(in:  CGRect(origin: CGPoint(x: -self.size.width/2, y: -self.size.height/2), size: size))
        }
        
        return image
    }
}