代码分享

写的不会好请多多指教

调整图片大小

extension UIImage {
    
    /// 调整image大小
    public func reSize(size: CGSize) -> UIImage {
        let newSize = CGSize(width: size.width * self.scale, height: size.height * self.scale)
        UIGraphicsBeginImageContext(newSize)
        self.draw(in: CGRect(origin: CGPoint.zero, size: newSize))
        let backImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return UIImage(cgImage: backImage!.cgImage!, scale: self.scale, orientation: UIImage.Orientation.up)
    }
    
    /// 子线程中调整大小
    public func asyncReSize(size: CGSize, back: @escaping (UIImage) -> Void) {
        DispatchQueue.global().async {
            let backValue = self.reSize(size: size)
            DispatchQueue.main.async {
                back(backValue)
            }
        }
    }
}
````