方法一:
如下代码:
     @objc func saveBtnClick(){         let frame = view.frame         UIGraphicsBeginImageContext(frame.size)         view.layer.render(in: UIGraphicsGetCurrentContext()!)         let image = UIGraphicsGetImageFromCurrentImageContext()         UIGraphicsEndImageContext()         self.loadImage(image: image!)     }               func loadImage(image:UIImage){         UIImageWriteToSavedPhotosAlbum(image, self, #selector(self.image(image:didFinishSavingWithError:contextInfo:)), nil)     }               @objc func image(image: UIImage, didFinishSavingWithError: NSError?,contextInfo: AnyObject)     {         if didFinishSavingWithError != nil         {             print("error!")             return         }                  print("保存成功")     }
 
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实测效果在IOS 12上可用,但是保存的质量不高。
方法二:
保存UIview
func UIImageWriteToSavedPhotosAlbum(_ image: UIImage, _ completionTarget: Any?, _ completionSelector: Selector?, _ contextInfo: UnsafeMutableRawPointer?)
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最后在info.plist中加入权限:

UIimageView用法参考:http://www.hangge.com/blog/cache/detail_534.html