关于OC和swift项目中图片压缩的问题

好多商城类的项目都有很多图片展示,这样会导致APP内存使用很高,因而我们的app使用起来感觉不流畅很卡,所以在我们上传图片之前最好是对图片做一下处理.使用系统的这两个方法并不能做到更好的优化(UIImagePNGRepresentation(image)),UIImageJPEGRepresentation(image,0.5)

以下最简单的方法是重绘图片:

oc代码:

```

//重新绘制图片,做到缩放功能

+(UIImage*)drawImage:(UIImage*)image width:(CGFloat)width {

CGFloatheight = (image.size.height/ image.size.width) * width;

CGSizesize =CGSizeMake(width, height);

UIGraphicsBeginImageContext(size);

[imagedrawInRect:CGRectMake(0,0, size.width, size.height)];

UIImage*newImage =UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

returnnewImage;

}

```

swift代码:

```

//重新绘制图片,做到缩放功能

classfuncdrawImage(image :UIImage, width :CGFloat) ->UIImage? {

letheight = (image.size.height/ image.size.width) * width

letsize =CGSize(width: width, height: height)

UIGraphicsBeginImageContext(size)

image.draw(in:CGRect(x:0, y:0, width: size.width, height: size.height))

letnewImage =UIGraphicsGetImageFromCurrentImageContext()

UIGraphicsEndImageContext()

returnnewImage ??nil

}

```