如何修复加载我自己班级的Webview URL时出现黑屏 [英] How to fix black screen in load of webview url from my own class

问题描述

我正在创建一个SDK来从用户和加载获取url。所以我正在用WKWebview创建我自己的类。但我遇到一些关于实例成员webView不能用于类型MyWebView(UIview)

的问题

我的代码：

import Foundation
import WebKit

public class MyWebView: UIView, WKNavigationDelegate {

    // initialize the view
     var webView: WKWebView!

    // get the url and load the page
    public func passUrl(url: String) {
        guard let url = URL(string: url) else { return }
        webView = WKWebView()
        webView.navigationDelegate = self
        webView.load(URLRequest(url: url))
        webView.allowsBackForwardNavigationGestures = true
        webView.addObserver(self, forKeyPath: "URL", options: .new, context: nil)
    }
    
    // Observe value
    override public func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
        if let key = change?[NSKeyValueChangeKey.newKey] {
            print("URL Changes: (key)")
            let alert = UIAlertController(title: "URL Changed", message: "(key)", preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: "Yes", style: .default, handler: nil))
            alert.addAction(UIAlertAction(title: "No", style: .cancel, handler: nil))
            self.window?.rootViewController?.present(alert, animated: true, completion: nil)
        }
    }
    
}

我的视图控制器：

class ViewController: UIViewController {

    var webView =  MyWebView()
    

    override func viewDidLoad() {
        super.viewDidLoad()
        view = webView
        webView.passUrl(url: "https://www.swiggy.com")
    }
}

当我运行时，我的屏幕显示为黑色。不知道我在做什么王。任何帮助都是最好的。

谢谢

推荐答案

尝试此代码。经过测试并为我工作。 MyWebView类

import Foundation
import WebKit

public class MyWebView: UIView, WKNavigationDelegate {

// initialize the view
let view: WKWebView = {
    let view = WKWebView()
    return view
}()

// get the url and load the page
public func passUrl(url: String) {
    guard let url = URL(string: url) else { return }
    view.navigationDelegate = self
    view.load(URLRequest(url: url))
    view.allowsBackForwardNavigationGestures = true
    view.addObserver(self, forKeyPath: "URL", options: .new, context: nil)
}

// Observe value
override public func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
    if let key = change?[NSKeyValueChangeKey.newKey] {
        print("URL Changes: (key)")
        let alert = UIAlertController(title: "URL Changed", message: "(key)", preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "Yes", style: .default, handler: nil))
        alert.addAction(UIAlertAction(title: "No", style: .cancel, handler: nil))
        self.window?.rootViewController?.present(alert, animated: true, completion: nil)
    }
}

public override init(frame: CGRect) {
    super.init(frame: frame)
    setupView()
}

required init?(coder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

private func setupView() {
    view.translatesAutoresizingMaskIntoConstraints = false
    addSubview(view)
    NSLayoutConstraint.activate([
        view.topAnchor.constraint(equalTo: topAnchor),
        view.leadingAnchor.constraint(equalTo: leadingAnchor),
        view.trailingAnchor.constraint(equalTo: trailingAnchor),
        view.bottomAnchor.constraint(equalTo: bottomAnchor),
    ])
}
}

视图控制器类

import UIKit

class ViewController: UIViewController {

var webView =  MyWebView()

override func viewDidLoad() {
    super.viewDidLoad()
    webView.passUrl(url: "https://www.swiggy.com")
}

override func loadView() {
    view = webView
}
}

如果这不能解决问题，请让我知道。

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