添加PDF文件中的网站链接无效

Question

我正在生成PDF文件并在PDF文件的页脚中添加链接。它将字符串显示为突出显示，但不会重定向到网站。

我正在使用Swift 3.这是我的代码：

class CustomPrintPageRenderer: UIPrintPageRenderer {

 //some code here

 override func drawFooterForPage(at pageIndex: Int, in footerRect: CGRect)  {

    let font = UIFont.systemFont(ofSize: 10)

    let textAttributes = [NSFontAttributeName:font, NSForegroundColorAttributeName:UIColor.darkGray]
    let text = NSAttributedString(string: "This is a computer generated document, ", attributes: textAttributes)

    let website = NSMutableAttributedString.init(string: "Click here to visit website.")
    website.addAttribute(NSLinkAttributeName, value: NSURL.init(string: "www.google.com")!, range: NSMakeRange(0, website.length))

    let footerContent = NSMutableAttributedString()

    footerContent.append(text)
    footerContent.append(website)

    let textSize = getTextSize(text: footerContent.string, font: font)
    let centerX = footerRect.size.width/2 - textSize.width/2
    let centerY = footerRect.origin.y + 10
    footerContent.draw(at: CGPoint(x: centerX, y: centerY))
  }
}