当网页中没有网络执行操作时，关闭 WKWebview

Question

我正在WKWebView加载注册表单，当用户填写注册表单并点击"注册"按钮时，它将被带到注册成功页面。

如果用户在点击"注册"按钮时失去网络连接，如何捕获无网络错误？

如果用户在加载注册表单之前未连接到网络，则以下代码有效：

func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
if(error.localizedDescription == "The Internet connection appears to be offline.") {
print("Network error")
self.presentingViewController?.dismiss(animated: true, completion: {
let alert = UIAlertController(title: "No Network", message: "No network, please check your internet connection and try again.", preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK".localisedString(), style: .default, handler: nil))
let topC = AppConstants.getRootController().topMostViewController()
topC.present(alert, animated: true, completion: nil)
})
}
}

Answer 1

• 您首先关闭了当前ViewController，然后您正在尝试UIAlertController鞋，也许这就是为什么它不起作用的原因，否则您的代码是正确的

• 尝试先显示alert，然后关闭当前ViewController

  如下所示

  func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
  if(error.localizedDescription == "The Internet connection appears to be offline.")
  {
  print("Network error")
  let alert = UIAlertController(title: "No Network", message: "No network, please check your internet connection and try again.", preferredStyle: .alert)
  let ok = UIAlertAction(title: "OK", style: .default) { ( _ ) in
  let topC = self.storyboard!.instantiateViewController(withIdentifier: "cal") as! cal
  self.present(topC, animated: true, completion: nil)
  }
  alert.addAction(ok)
  self.present(alert, animated: true) {
  self.presentingViewController?.dismiss(animated: true, completion: nil)
  }
  }
  }
  

• 试试这段代码，这将起作用(代码中缺少的内容如下(

  1. okAlertAction 未添加到alertAlertViewController 中

  2. topC已初始化，但未ok操作中显示。