[笔记] Swift-图片裁剪、压缩、转换

图片裁剪：
新建UIImage扩展 Image类

/// 裁剪图片
    func cropToSize(rect: CGRect) -> UIImage {
        var newRect = rect
        newRect.origin.x *= self.scale
        newRect.origin.y *= self.scale
        newRect.size.width *= self.scale
        newRect.size.height *= self.scale
        let cgimage = self.cgImage?.cropping(to: newRect)
        let resultImage = UIImage(cgImage: cgimage!, scale: self.scale, orientation: self.imageOrientation)
        return resultImage
    }

/// 压缩图片数据-不压尺寸
    ///
    /// - Parameters:
    ///   - maxLength: 最大长度   maxLength/1024 = kb
    /// - Returns:
    func compressImageTolength(maxLength: Int) -> Data? {
        
        guard let vData = self.jpegData(compressionQuality: 1) else {
            return nil
        }
        JJPrint("压缩前kb：\(Double((vData.count)/1024))")
        if vData.count < maxLength {
            return vData
        }
        var compress:CGFloat = 0.9
        guard var data = self.jpegData(compressionQuality: compress) else {
            return nil
        }
        while data.count > maxLength && compress > 0.02 {
            JJPrint("压缩比：\(compress)")
            compress -= 0.07
            data = self.jpegData(compressionQuality: compress)!
        }
        JJPrint("压缩后kb：\(Double((data.count)/1024))")
        return data
    }

/// UIColor-->UIImage
    func imageWithColor(color: UIColor, size: CGSize) -> UIImage {
        
        let rect: CGRect = CGRect(x: 0, y: 0, width: size.width, height: size.height)
        
        UIGraphicsBeginImageContext(rect.size)
        
        let context: CGContext = UIGraphicsGetCurrentContext()!
        
        context.setFillColor(color.cgColor)
        
        context.fill(rect)
        
        let image = UIGraphicsGetImageFromCurrentImageContext()
        
        UIGraphicsGetCurrentContext()
        
        return image!
    }

/**
     *  重设图片大小
     */
    func reSizeImage(reSize:CGSize) -> UIImage {
        //UIGraphicsBeginImageContext(reSize);
        UIGraphicsBeginImageContextWithOptions(reSize,false,UIScreen.main.scale)
        self.draw(in: CGRect(x:0,y:0,width:reSize.width,height:reSize.height))
        let reSizeImage:UIImage = UIGraphicsGetImageFromCurrentImageContext() ?? UIImage()
        UIGraphicsEndImageContext()
        return reSizeImage
    }
    
    /**
     *  等比率缩放
     */
    func scaleImage(scaleSize:CGFloat) -> UIImage {
        let reSize = CGSize(width:self.size.width * scaleSize,height:self.size.height * scaleSize)
        return reSizeImage(reSize: reSize)
    }

Over !