如何在SwiftUI中点击按钮打开web视图

Question

这是我的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)
}
}
}

这是我在"内容"视图中的按钮。

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

事实上，当我点击它时，什么都不会发生，但当我把它移到按钮之外时，它会自动打开。

我的问题是，如何点击按钮打开WebView，我对SwiftUI很陌生。

谢谢。

Answer 1

您的调用方式不对。使用此

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")!)
}
}
}