如何在 SwiftUI 中單擊按鈕打開 web 視圖？

Question

這是我的 WebView

struct Webview: UIViewControllerRepresentable {
    let url: URL

    func makeUIViewController(context: Context) -> WebviewController {
        let webviewController = WebviewController()

        let request = URLRequest(url: self.url, cachePolicy: .returnCacheDataElseLoad)
        webviewController.webview.load(request)

        return webviewController
    }

    func updateUIViewController(_ webviewController: WebviewController, context: Context) {
        //
    }
}

class WebviewController: UIViewController, WKNavigationDelegate {
    lazy var webview: WKWebView = WKWebView()
    lazy var progressbar: UIProgressView = UIProgressView()

    deinit {
        self.webview.removeObserver(self, forKeyPath: "estimatedProgress")
        self.webview.scrollView.removeObserver(self, forKeyPath: "contentOffset")
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        self.webview.navigationDelegate = self
        self.view.addSubview(self.webview)

        self.webview.frame = self.view.frame
        self.webview.translatesAutoresizingMaskIntoConstraints = false
        self.view.addConstraints([
            self.webview.topAnchor.constraint(equalTo: self.view.topAnchor),
            self.webview.bottomAnchor.constraint(equalTo: self.view.bottomAnchor),
            self.webview.leadingAnchor.constraint(equalTo: self.view.leadingAnchor),
            self.webview.trailingAnchor.constraint(equalTo: self.view.trailingAnchor),
        ])

        self.webview.addSubview(self.progressbar)
        self.setProgressBarPosition()

        webview.scrollView.addObserver(self, forKeyPath: "contentOffset", options: .new, context: nil)

        self.progressbar.progress = 0.1
        webview.addObserver(self, forKeyPath: "estimatedProgress", options: .new, context: nil)
    }

    func setProgressBarPosition() {
        self.progressbar.translatesAutoresizingMaskIntoConstraints = false
        self.webview.removeConstraints(self.webview.constraints)
        self.webview.addConstraints([
            self.progressbar.topAnchor.constraint(equalTo: self.webview.topAnchor, constant: self.webview.scrollView.contentOffset.y * -1),
            self.progressbar.leadingAnchor.constraint(equalTo: self.webview.leadingAnchor),
            self.progressbar.trailingAnchor.constraint(equalTo: self.webview.trailingAnchor),
        ])
    }

    // MARK: - Web view progress
    override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
        switch keyPath {
        case "estimatedProgress":
            if self.webview.estimatedProgress >= 1.0 {
                UIView.animate(withDuration: 0.3, animations: { () in
                    self.progressbar.alpha = 0.0
                }, completion: { finished in
                    self.progressbar.setProgress(0.0, animated: false)
                })
            } else {
                self.progressbar.isHidden = false
                self.progressbar.alpha = 1.0
                progressbar.setProgress(Float(self.webview.estimatedProgress), animated: true)
            }

        case "contentOffset":
            self.setProgressBarPosition()

        default:
            super.observeValue(forKeyPath: keyPath, of: object, change: change, context: context)
        }
    }
}

這是我在內容視圖中的按鈕。

Button(action: {
    Webview(url: URL(string:"https://www.google.com")!)
 }) 
   {
      Image("go")
   }                 
 }

實際上，當我單擊它時，什么都沒有發生，但是當我將它移到按鈕之外時，它會自動打開。

我的問題是，如何在單擊按鈕時打開 WebView，我對 SwiftUI 很陌生。

謝謝你。

Answer 1

你打電話的方式不對。 用這個

struct ContentView: View {
    
    @State private var isShowingWebView: Bool = false
    
    var body: some View {
        Button(action: {
            isShowingWebView = true
            //            Webview(url: URL(string:"https://www.google.com")!) <<-- Remove
        })
        {
            Text("go")
        }
        .sheet(isPresented: $isShowingWebView) {
            Webview(url: URL(string:"https://www.google.com")!)
        }
    }
}