Swift：没有互联网连接时如何在 webview 中显示错误消息？ [复制]

Question

我制作了这个网页视图，我想在使用应用程序时在没有互联网连接或失去互联网连接时显示错误消息。

这是我的代码：

import UIKit


class FirstViewController: UIViewController, UIWebViewDelegate {

    @IBOutlet weak var webView1: UIWebView!

    var refreshControl:UIRefreshControl?

    @IBOutlet weak var activityIndicator: UIActivityIndicatorView!

    override func viewDidLoad() {
        super.viewDidLoad()

        webView1.delegate = self


        let url = URL(string: "https://pharmacyuni.blogspot.com")
        webView1.loadRequest(URLRequest(url: url!))
    }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func goBack(_ sender: Any) {
        webView1.goBack()
    }


    func webViewDidStartLoad(_ webView: UIWebView)
    {
        activityIndicator.startAnimating()
    }
    func webViewDidFinishLoad(_ webView: UIWebView)
    {
        activityIndicator.stopAnimating()
    }


    @IBAction func refreshButton(_ sender: Any) {
        webView1.reload()
    }

}

Answer 1

你可以使用委托方法：

func webView(_ webView: UIWebView, didFailLoadWithError error: Error) {
    print("webview did fail load with error: \(error)")

    let message: String = error.localizedDescription

    let alert = UIAlertController(title: "something", message: message, preferredStyle: .alert)
    alert.addAction(UIAlertAction(title: "Ok", style: .default) { action in
    // use action here
    })
    self.present(alert, animated: true)
}