试图让 webView 一个接一个地加载 2 个 URL

Question

我试图让它在一个完成加载后加载 2 个 webview 然后它会转到下一个并开始加载那个，如果它们都加载了，它将发送通知。

在

之后会报错

        @IBAction func MybuttonAction(_ sender: Any) {

    if !googleLoaded {

        googleLoaded = true
        let url = URL(string: "https://google.com")
        let requestObj = URLRequest(url: url!)
        webView.loadRequest(requestObj)
        print("Google loaded")
        let url1 = URL(string: "https://yahoo.com")
        let requestObj1 = URLRequest(url: url1!)
        webView.loadRequest(requestObj1)
        print("yahoo loaded")

    } else if !yahooLoaded {

        yahooLoaded = true

        let alertController = UIAlertController(title: "ThankYou", message: "Both Views have finished loading", preferredStyle: .alert)

        let defaultAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
        alertController.addAction(defaultAction)

        self.present(alertController, animated: true, completion: nil)
        self.aviLoadingSpinner.stopAnimating()
    }
}


func webViewDidFinishLoad(_ webView: UIWebView) {

}

Answer 1

您必须使用 UIWebViewDelegate webViewDidFinishLoad。当请求完成时调用该方法。

import WebKit

class yourViewController: UIViewController, UIWebViewDelegate {

 @IBoutlet weak var webView: UIWebView!

 var googleLoaded: Bool = false 
 var yahooLoaded: Bool = false 

 override func viewDidLoad() {
     self.webView.delegate = self
 }         

 func webViewDidFinishLoad(_ webView: UIWebView) {

     if !googleLoaded { 

         googleLoaded = true
         let url = URL(string: "https://yahoo.com")
         let requestObj = URLRequest(url: url!)
         webView.loadRequest(requestObj) 

     } else if !yahooLoaded { 

         yahooLoaded = true
         let alertController = UIAlertController(title: "ThankYou", message: "Both Views have finished loading", preferredStyle: .alert)

         let defaultAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
         alertController.addAction(defaultAction)

         self.present(alertController, animated: true, completion: nil)
         self.aviLoadingSpinner.stopAnimating() 
     }
 }

 @IBAction func MybuttonAction(_ sender: Any) {

     let url = URL(string: "https://google.com")
     let requestObj = URLRequest(url: url!)
     webView.loadRequest(requestObj)
}

Answer 2

所以如果我理解正确的话，你现在拥有的是

• 检查 webview 是否正在加载

• 第一次按下按钮时它不应该加载，所以加载 yahoo

• 第二次按下按钮时，它会看到 webview 正在加载，因此它会加载 google.com

• 然后检查它是否完成加载。

但有一些问题是，您必须按两次按钮，我认为您不希望这样做。你现在拥有它的方式不会在你的 cmets 告诉我的雅虎之前加载谷歌。如果你这样做，它会开始加载谷歌，而雅虎可能仍在加载。 我会这样做：

let url = URL (string: "https://google.com")
let requestObj = URLRequest(url: url!)
webView.loadRequest(requestObj)

while webview.IsLoading{
// you should wait here
}
let url = URL (string: "https://yahoo.com")
let requestObj = URLRequest(url: url!)
webView.loadRequest(requestObj)

while webview.IsLoading{
//You should wait again here     
}


//Now you don't have to check anymore to see if they are done
let alertController = UIAlertController(title: "ThankYou", message: "Both Views have finished loading", preferredStyle: .alert)

let defaultAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
alertController.addAction(defaultAction)

self.present(alertController, animated: true, completion: nil)
self.aviLoadingSpinner.stopAnimating()

这样你首先加载谷歌。你等到它完成加载。 然后你加载雅虎并等待。 然后你开始通知。