最新swift4.0 图片进行尺寸大小及体积压缩

p.p1 { margin: 0.0px 0.0px 0.0px 0.0px; font: 15.0px Menlo; color: #4dbf56; background-color: #282b35 }
p.p2 { margin: 0.0px 0.0px 0.0px 0.0px; font: 15.0px Menlo; color: #ffffff; background-color: #282b35 }
p.p3 { margin: 0.0px 0.0px 0.0px 0.0px; font: 15.0px Menlo; color: #ffffff; background-color: #282b35; min-height: 18.0px }
p.p4 { margin: 0.0px 0.0px 0.0px 0.0px; font: 15.0px Menlo; color: #00afca; background-color: #282b35 }
span.s1 { color: #c2349b }
span.s2 { color: #00afca }
span.s3 { color: #8b84cf }
span.s4 { color: #ffffff }

///图片压缩方法

class func resetImgSize(sourceImage : UIImage,maxImageLenght : CGFloat,maxSizeKB : CGFloat) -> Data {

var maxSize = maxSizeKB

var maxImageSize = maxImageLenght

if (maxSize <= 0.0) {

maxSize = 1024.0;

}

if (maxImageSize <= 0.0)  {

maxImageSize = 1024.0;

}

//先调整分辨率

var newSize = CGSize.init(width: sourceImage.size.width, height: sourceImage.size.height)

let tempHeight = newSize.height / maxImageSize;

let tempWidth = newSize.width / maxImageSize;

if (tempWidth > 1.0 && tempWidth > tempHeight) {

newSize = CGSize.init(width: sourceImage.size.width / tempWidth, height: sourceImage.size.height / tempWidth)

}

else if (tempHeight > 1.0 && tempWidth < tempHeight){

newSize = CGSize.init(width: sourceImage.size.width / tempHeight, height: sourceImage.size.height / tempHeight)

}

UIGraphicsBeginImageContext(newSize)

sourceImage.draw(in: CGRect.init(x: 0, y: 0, width: newSize.width, height: newSize.height))

let newImage = UIGraphicsGetImageFromCurrentImageContext()

UIGraphicsEndImageContext()

var imageData = UIImageJPEGRepresentation(newImage!, 1.0)

var sizeOriginKB : CGFloat = CGFloat((imageData?.count)!) / 1024.0;

//调整大小

var resizeRate = 0.9;

while (sizeOriginKB > maxSize && resizeRate > 0.1) {

imageData = UIImageJPEGRepresentation(newImage!,CGFloat(resizeRate));

sizeOriginKB = CGFloat((imageData?.count)!) / 1024.0;

resizeRate -= 0.1;

}

return imageData!

}