SwiftUi Button action reload WebView

Question

I have simple SwiftUi WebView codes and I want to reload WebView when my button clicked (I added only function and simple codes).

class myWebViewController: UIViewController, WKNavigationDelegate {


    var webview: WKWebView

    func reload(){
        webview.reload()
    }

}


   override func viewDidLoad() {
        super.viewDidLoad()


       let overlayView = UIHostingController(rootView: NewRecordButton())
       addChild(overlayView)

       overlayView.view.backgroundColor = UIColor.clear
        overlayView.view.frame = CGRect(x: 0, y: 0, width: 60, height: 60)
       overlayView.view.isUserInteractionEnabled = true


       self.view.addSubview(overlayView.view)
       overlayView.didMove(toParent: self)

    }

    struct NewRecordButton: View {
        @State var color = false
        var body: some View {

                    HStack {
                        Spacer()
                       Button(action: {

                        myWebViewController().webview.reload() // HERE MY ACTION BUT DONT WORK

                                           }, label: {
                                               Text("+")
                                               .font(.system(.largeTitle))
                                               .frame(width: 35, height: 35)
                                               .foregroundColor(Color.white)
                                               .padding(.bottom, 7)


                                           })
                                           .background(Color.blue)
                                           .cornerRadius(38.5)
                                           .padding()
                                           .shadow(color: Color.black.opacity(0.3),
                                                   radius: 3,
                                                   x: 3,
                                                   y: 3)
             }

        }
    }
}

Answer 1

myWebViewController() 创建一个新的 web 视图实例

Answer 2

You can make this with NotificationCenter, register observer in class where you need to refresh web view, for example in viewDidLoad:

NotificationCenter.default.addObserver(self, selector: #selector(funcUpdateWebView(notification:)), name: NSNotification.Name(rawValue: "updateWebView"), object: nil)

Then setup function for update (also in the class where you need web view to be updated)

@objc func funcUpdateWebView(notification: NSNotification) {
    webview.reload()
}

Then post notification from another view controller (instead of myWebViewController().webview.reload() ) like this:

NotificationCenter.default.post(name: NSNotification.Name("updateWebView"), object: nil)

This will do the work.

Also don't forget to deinit this notification in first class outside any functions:

deinit {
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name(rawValue: "updateWebView"), object: nil)
}

UPDATE:

Another way is to make delegate.

protocol UpdateView {
    func update()
}

Subscribe to UpdateView delegate by adding UpdateView to the class myWebViewController.

class myWebViewController: UIViewController, WKNavigationDelegate, UpdateView {

in NewRecordButton create weak var delegate:

struct NewRecordButton: View {
    weak var delegate: UpdateView?

    // Replace "myWebViewController().webview.reload()" with this line
    // This will start update() function that will update webview in myWebViewController
    self.delegate.update()

In myWebViewController setup delegate for newRecordButton and function that will reload webView.

class myWebViewController: UIViewController, WKNavigationDelegate, UpdateView {
    let NewRecordButton = NewRecordButton()
    newRecordButton.delegate = self

    ...
    func update() {
       webview.reload()
    }
    ...
}