Swift3.0保存图片到相册

网上的教程都比较早，分享一下swift3.0的

@IBAction func saveLingfuImage(_ sender: UIBarButtonItem) {
        let customImage = UIImage(named: (lingfu?.image)!)
        UIImageWriteToSavedPhotosAlbum(customImage!, self, #selector(savedOK(image:didFinishSavingWithError:contextInfo:)), nil)

        //UIImageWriteToSavedPhotosAlbum(image!, nil, nil, nil)
        
        
    }


// 提示：参数 空格 参数别名: 类型
    func savedOK(image: UIImage, didFinishSavingWithError error: NSError?, contextInfo: AnyObject) {
        print("---")
        
        // if didFinishSavingWithError != nil {
        if error != nil {
            UIAlertView(title: "错误", message: error?.localizedDescription, delegate: nil, cancelButtonTitle: "确定").show()

            return
        }
        print("OK")
        UIAlertView(title: "提示", message: "保存成功", delegate: nil, cancelButtonTitle: "确定").show()
        
    }