ios - swift 3 : Preload SecondViewController's WKWebView ahead of click

Question

我需要一些帮助。我想在第一个 View Controller 中的 webView 完成后在第二个 View Controller 中预加载我的 webView。

我相信我需要使用通知中心发布/观察来调用第二个 View Controller 中的 loadWebView 函数，但不知道如何操作。如有任何建议，我们将不胜感激。

<小时/>

FirstViewController.swift

import UIKit;
import WebKit;

class FirstViewController: UIViewController, WKNavigationDelegate {


    let webView:WKWebView = WKWebView(frame: CGRectMake(0, 0, UIScreen.main.bounds.width, UIScreen.main.bounds.height))

    func webView(_ webView: WKWebView,
             didFinish navigation: WKNavigation!) {
        print("loaded!")
        webView.isHidden = false

        }

    override func viewDidLoad() {
        super.viewDidLoad()
        let url = URL(string: "https://www.google.com")
        webView.navigationDelegate = self
        webView.load(URLRequest(url: url!))
        webView.isHidden = true
        self.view.addSubview(webView)

    }

}

SecondViewController.swift

import UIKit
import WebKit

class SecondViewController: UIViewController, WKNavigationDelegate {

    let webView:WKWebView = WKWebView(frame: CGRectMake(0, 0, UIScreen.main.bounds.width, UIScreen.main.bounds.height))


    func webView(_ webView: WKWebView,
             didFinish navigation: WKNavigation!) {
        print("loaded!")
        webView.isHidden = false
    }

    override func viewDidLoad() {
        super.viewDidLoad()


    }

    func loadWebView() {
        let url = URL(string: "https://www.amazon.com")
        webView.navigationDelegate = self
        webView.load(URLRequest(url: url!))
        webView.isHidden = true
        self.view.addSubview(webView)
    }


}

Answer 1

在第一个 VC 中:

func webView(_ webView: WKWebView,
             didFinish navigation: WKNavigation!) {

   //Post notification
   NotificationCenter.default.post(name: NSNotification.Name(rawValue: "WebViewFinishedLoading"), object: nil)
}

在第二个 VC 中:

override func viewDidLoad() {
        super.viewDidLoad()

   // Add observer for your notification
    NotificationCenter.default.addObserver(self, selector: #selector(loadWebView), name: NSNotification.Name(rawValue: "WebViewFinishedLoading"), object: nil)
    }

//Remove observer in deinit
 deinit {    
    NotificationCenter.default.removeObserver(self)
 }