在 SwiftUI 中使用 WKWebView 时如何拦截链接导航? [英] How do I intercept link navigation when using WKWebView in SwiftUI?

问题描述

我在 SwiftUI 应用中使用 WKWebView.我的包中有一个 HTML 文件，我最初将它加载到 WKWebView 中.该文件中有一个链接，如果点击，我想在外部浏览器中打开该链接.我使用以下代码创建了 WKWebView:

I'm using WKWebView in a SwiftUI app. I have an HTML file in my bundle that I'm initially loading into the WKWebView. The file has a link in it that I would like to open in an external browser if tapped. I've created the WKWebView using the following code:

import SwiftUI
import WebKit

struct WebView: UIViewRepresentable {
    typealias UIViewType = WKWebView

    let request: URLRequest

    func makeUIView(context: UIViewRepresentableContext<WebView>) -> WKWebView {
        let webView = WKWebView()
        let delegate = WVNavigationDelegate()
        webView.navigationDelegate = delegate
        return webView
    }

    func updateUIView(_ uiView: WKWebView, context: UIViewRepresentableContext<WebView>) {
        uiView.load(request)
    }
}

我使用以下代码创建了委托:

I've created the delegate using this code:

import Foundation
import WebKit

class WVNavigationDelegate: NSObject, WKNavigationDelegate {
    func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
        switch navigationAction.navigationType {
        case WKNavigationType.linkActivated:
            UIApplication.shared.open(navigationAction.request.url!, options: [:], completionHandler: nil)
            decisionHandler(.cancel)
        default:
            decisionHandler(.allow)
        }
    }
}

如果我注释掉创建和分配委托的行，除了在外部打开的链接外，一切正常.编译这些行后，WebView 中不会加载任何内容.我在委托中的函数开头放置了一个 print() 语句，它甚至没有被执行.我在这里做错了什么?

If I comment out the lines creating and assigning the delegate, everything works fine with the exception of links opening externally. With those lines compiled in, nothing loads in the WebView. I put a print() statement at the beginning of the function in the delegate and it didn't even get executed. What am I doing wrong here?

推荐答案

navigationDelegate 很弱，所以在提供的代码中它会在从 makeUIView 退出时立即释放.

The navigationDelegate is weak so in the provided code it is released as soon as exit from makeUIView.

解决方案是将其保留为成员，如

The solution is to keep it as member, as in

struct WebView: UIViewRepresentable {
    typealias UIViewType = WKWebView

    let request: URLRequest
    private let delegate = WVNavigationDelegate()   // << here !!

    func makeUIView(context: UIViewRepresentableContext<WebView>) -> WKWebView {
        let webView = WKWebView()
        webView.navigationDelegate = delegate
        return webView
    }

    func updateUIView(_ uiView: WKWebView, context: UIViewRepresentableContext<WebView>) {
        uiView.load(request)
    }
}

这篇关于在 SwiftUI 中使用 WKWebView 时如何拦截链接导航?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！