URL不会打开swift 3

Question

@IBAction func download(_ sender: Any) {
    if let url = URL(string: "\(imgURL)") {
        UIApplication.shared.openURL(url as URL)
    }
    print(imgURL)
}

如果我按下按钮，网址就不会打开。 consol说正确的网址：https://scontent-ams3-1.cdninstagram.com/t51.2885-19/18514045_212505245924563_1350282415863496704_a.jpg但网址不会打开。请帮忙！感谢

                   let urlstr = "\(profile_pic_url_hd)"
                        if var comps = URLComponents(string: urlstr) {
                            var path = comps.path
                            var pathComps = path.components(separatedBy: "/")
                            pathComps.remove(at: 2) // this removes the s320x320
                            path = pathComps.joined(separator: "/")
                            comps.path = path
                            if let newStr = comps.string {
                                print(newStr)
                                self.imgURL = "\(newStr)"
                            }
                        }