Navigation bar with large title shrinks when webview is loaded

问题

In viewcontroller, I'm loading a webview(WKWebview) with large navigation title enabled. The problem is its showing the large navigation bar and title perfectly before the webview gets loaded once the webview got loaded it shrinks to normal. Anyhelp would be appreciated.

Thanks in advance...!

回答1:

Swift4, Swift5 :

The reason of this issue is your navigationBar height is changing when you webView starts loading the page. so using viewLayoutMarginsDidChange() we can change navigationBar height.
viewLayoutMarginsDidChange() Called to notify the view controller that the layout margins of its root view changed. This method will get called every time when navigationBar height changes.

Below code worked for me

import WebKit

class ViewController: UIViewController, WKNavigationDelegate {

    private var webView: WKWebView!
    var didChange = false //Set true when we have to update navigationBar height in viewLayoutMarginsDidChange()

    override func viewLayoutMarginsDidChange() {
        if didChange {
            print("Height : - \(self.navigationController?.navigationBar.frame.size.height)")
        // set NavigationBar Height here    
           self.navigationController!.navigationBar.frame = CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: 96.0)
            didChange.toggle() 
            }
        }

    override func viewDidLoad() {
        super.viewDidLoad()

    let appearance = UIBarButtonItem.appearance()
    appearance.setBackButtonTitlePositionAdjustment(UIOffset.init(horizontal: 0.0, vertical: -60), for: .default)

    self.navigationItem.title = "WebView"
    self.navigationController?.navigationBar.isTranslucent = true
    self.navigationController?.navigationBar.tintColor = UIColor.black
    self.navigationController?.navigationBar.prefersLargeTitles = true

    webView = WKWebView(frame: CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: self.view.frame.size.height))
    webView.navigationDelegate = self
    view = webView


    let myURL = URL(string:"https://google.com")
    let myRequest = URLRequest(url: myURL!)
    webView.load(myRequest)

    }


    func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
        print("Did Start")
      //webView page starts loading
        didChange = true
    }

}

来源：https://stackoverflow.com/questions/53728599/navigation-bar-with-large-title-shrinks-when-webview-is-loaded

标签

ios

swift

uinavigationbar

wkwebview