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我一直在尝试创建一个 TabView,PageIndexViewStyle其中每个页面都是一个包含图像和 WebView 的 ScrollView。当我在 TabView 之外创建页面时,@ Asperi的示例代码效果很好,但是当我在 TabView 内移动内容时,第二页上的 WebView 不会显示。

在此处输入图像描述

import SwiftUI
import WebKit

struct Webview : UIViewRepresentable {
    @Binding var dynamicHeight: CGFloat
    var webview: WKWebView = WKWebView()
    
    class Coordinator: NSObject, WKNavigationDelegate {
        var parent: Webview
        
        init(_ parent: Webview) {
            self.parent = parent
        }
        
        func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
            webView.evaluateJavaScript("document.documentElement.scrollHeight", completionHandler: { (height, error) in
                DispatchQueue.main.async {
                    self.parent.dynamicHeight = height as! CGFloat
                }
            })
        }
    }
    
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
    
    func makeUIView(context: Context) -> WKWebView  {
        webview.scrollView.bounces = false
        webview.navigationDelegate = context.coordinator
        let htmlStart = "<HTML><HEAD><meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0, shrink-to-fit=no\"></HEAD><BODY>"
        let htmlEnd = "</BODY></HTML>"
        let dummy_html = """
                        <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec ut venenatis risus. Fusce eget orci quis odio lobortis hendrerit. Vivamus in sollicitudin arcu. Integer nisi eros, hendrerit eget mollis et, fringilla et libero. Duis tempor interdum velit. Curabitur</p>
                        <p>ullamcorper, nulla nec elementum sagittis, diam odio tempus erat, at egestas nibh dui nec purus. Suspendisse at risus nibh. Mauris lacinia rutrum sapien non faucibus. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec interdum enim et augue suscipit, vitae mollis enim maximus.</p>
                        <p>Fusce et convallis ligula. Ut rutrum ipsum laoreet turpis sodales, nec gravida nisi molestie. Ut convallis aliquet metus, sit amet vestibulum risus dictum mattis. Sed nec leo vel mauris pharetra ornare quis non lorem. Aliquam sed justo</p>
                        """
        let htmlString = "\(htmlStart)\(dummy_html)\(htmlEnd)"
        webview.loadHTMLString(htmlString, baseURL:  nil)
        return webview
    }
    
    func updateUIView(_ uiView: WKWebView, context: Context) {
    }
}


struct ContentView: View {
    @State private var webViewHeight: CGFloat = .zero
    var body: some View {
        TabView {
            ScrollView {
                VStack {
                    Image(systemName: "doc")
                        .resizable()
                        .scaledToFit()
                        .frame(height: 100)
                    Divider()
                    Webview(dynamicHeight: $webViewHeight)
                        .padding(.horizontal)
                        .frame(height: webViewHeight)
                }
            }
            
            ScrollView {
                VStack {
                    Image(systemName: "star")
                        .resizable()
                        .scaledToFit()
                        .frame(height: 100)
                    Divider()
                    Webview(dynamicHeight: $webViewHeight)
                        .padding(.horizontal)
                        .frame(height: webViewHeight)
                }
            }
        }
        .tabViewStyle(PageTabViewStyle())
        .indexViewStyle(PageIndexViewStyle(backgroundDisplayMode: .always))
    }
}
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1 回答 1

1

我不能确切地告诉你是什么导致了这种奇怪的行为,但设置解决了问题的selection参数。TabView据我了解,SwiftUI希望我们bindingTabView.

所以,改变

 TabView {

TabView(selection: $selectedtab) {
// Or
TabView(selection: .constant(1)) {

解决了。

于 2021-05-12T16:08:23.720 回答