我正在使用webkit视图来显示网站。
但是，如果我浏览该网站的任何位置，然后转到应用程序中的新选项卡，然后返回到webview工具包选项卡，则webpage仍然是我保留的位置。每次单击其他标签时，都需要刷新它，以便当用户转到它时始终在初始页面上。
我尝试了下面的代码，但是没有运气。
import UIKit import WebKit
class BookingPage: UIViewController, WKNavigationDelegate{
var webView: WKWebView!
override func loadView() {
webView = WKWebView()
webView.navigationDelegate = self
view = webView
}
override func viewDidLoad() {
super.viewDidLoad()
let url = URL(string: "https://www.bbc.co.uk")!
webView.load(URLRequest(url: url))
let refresh = UIBarButtonItem(barButtonSystemItem: .refresh, target: webView, action: #selector(webView.reload))
toolbarItems = [refresh]
navigationController?.isToolbarHidden = false
}
@IBAction func close(_ sender: Any) {
self.dismiss(animated: true, completion: nil)
} }
答案 0 :(得分：1)
为此，您需要处理WKWebview委托方法
我已经创建了一个使用WKWebview的示例，您可以在此处获得详细说明：WKWebView
我还将发布视图控制器的代码，以便您可以了解如何使用刷新以及前后导航。
import UIKit
import WebKit
class KTWebViewController: UIViewController {
private let webview = WKWebView()
@IBOutlet weak private var viewBase: UIView!
@IBOutlet weak private var viewClose: UIView!
@IBOutlet weak private var viewBottomBar: UIView!
@IBOutlet weak private var btnForward: UIButton!
@IBOutlet weak private var btnBack: UIButton!
@IBOutlet weak private var btnRefresh: UIButton!
@IBOutlet weak private var constraintCloseBottom: NSLayoutConstraint!
@IBOutlet weak var activityIndicator: UIActivityIndicatorView!
var url : String?
private var previousContentOffset : CGFloat = 0.0
private var barAnimationDuration = 0.5
override func viewDidLoad() {
super.viewDidLoad()
setupView()
addWebview()
if let finalUrl = URL(string: url ?? "https://github.com/tryWabbit") {
webview.load(URLRequest(url: finalUrl))
}
}
private func addShadows() {
let offset = CGSize(width: -1.0, height: -1.0)
let ridius : CGFloat = 5.0
viewBottomBar.addShadow(offset:offset , color: UIColor.lightGray, radius: ridius, opacity: 1.0)
viewClose.addShadow(offset:offset , color: UIColor.lightGray, radius: ridius, opacity: 1.0)
}
private func addWebview() {
webview.navigationDelegate = self
webview.uiDelegate = self
webview.scrollView.delegate = self
webview.frame = viewBase.frame
viewBase.insertSubview(webview, at: 0)
webview.translatesAutoresizingMaskIntoConstraints = false
viewBase.addConstraint(NSLayoutConstraint(item: viewBase , attribute: .top, relatedBy: .equal, toItem:webview , attribute: .top, multiplier: 1.0, constant: 0.0))
viewBase.addConstraint(NSLayoutConstraint(item: viewBase, attribute: .bottom, relatedBy: .equal, toItem: webview, attribute: .bottom, multiplier: 1.0, constant: 0.0))
viewBase.addConstraint(NSLayoutConstraint(item: viewBase, attribute: .leading, relatedBy: .equal, toItem: webview, attribute: .leading, multiplier: 1.0, constant: 0.0))
viewBase.addConstraint(NSLayoutConstraint(item: viewBase, attribute: .trailing, relatedBy: .equal, toItem: webview, attribute: .trailing, multiplier: 1.0, constant: 0.0))
}
private func setupView() {
addShadows()
viewClose.backgroundColor = UIColor.clear
viewBottomBar.backgroundColor = UIColor.clear
viewClose.addBlur()
viewBottomBar.addBlur()
viewClose.makeCircle = true
viewClose.clipsToBounds = true
}
class func getViewController() -> KTWebViewController {
return KTWebViewController.init(nibName: "KTWebViewController", bundle: nil)
}
//MARK :- Actions
@IBAction private func closeButtonPressed(_ sender: Any) {
if let navigation = self.navigationController {
navigation.popViewController(animated: true)
} else {
dismiss(animated: true, completion: nil)
}
}
@IBAction private func refreshButtonPressed(_ sender: Any) {
webview.reload()
}
@IBAction private func forwardPressed(_ sender: Any) {
if webview.canGoForward {
webview.goForward()
}
}
@IBAction private func backPressed(_ sender: Any) {
if webview.canGoBack {
webview.goBack()
}
}
private func showNavigationBar() {
guard constraintCloseBottom.constant != 0.0 else { return }
constraintCloseBottom.constant = 0.0
viewBottomBar.alpha = 0.0
viewClose.alpha = 0.0
UIView.animate(withDuration: barAnimationDuration) {
self.viewBottomBar.alpha = 1.0
self.viewClose.alpha = 1.0
self.viewBase.layoutIfNeeded()
}
}
private func hideNavigationBar() {
guard constraintCloseBottom.constant == 0.0 else { return }
constraintCloseBottom.constant = -(viewClose.frame.height)
viewBottomBar.alpha = 1.0
viewClose.alpha = 1.0
UIView.animate(withDuration: barAnimationDuration, animations: {
self.viewBottomBar.alpha = 0.0
self.viewClose.alpha = 0.0
self.viewBase.layoutIfNeeded()
})
}
}
extension KTWebViewController : WKNavigationDelegate{
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
activityIndicator.stopAnimating()
updateButtons(webView: webView)
}
func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
activityIndicator.stopAnimating()
updateButtons(webView: webView)
}
func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
activityIndicator.startAnimating()
}
private func updateButtons(webView:WKWebView) {
let enableColor = UIColor.black
let disableColor = UIColor.lightGray
let back = webView.canGoBack
let forward = webView.canGoForward
btnForward.isEnabled = forward
btnBack.isEnabled = back
btnForward.tintColor = forward ? enableColor : disableColor
btnBack.tintColor = back ? enableColor : disableColor
}
}
extension KTWebViewController : WKUIDelegate {
func webView(_ webView: WKWebView, createWebViewWith configuration: WKWebViewConfiguration, for navigationAction: WKNavigationAction, windowFeatures: WKWindowFeatures) -> WKWebView? {
if navigationAction.targetFrame == nil {
webview.stopLoading()
webview.load(navigationAction.request)
}
return nil
}
}
extension KTWebViewController : UIScrollViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let currentContentOffset = scrollView.contentOffset.y;
guard (currentContentOffset + webview.frame.height) < scrollView.contentSize.height else { return }
if currentContentOffset <= 0.0 {
showNavigationBar()
}else if (currentContentOffset > previousContentOffset) {
// scrolling towards the bottom
hideNavigationBar()
} else if (currentContentOffset < previousContentOffset) {
// scrolling towards the top
showNavigationBar()
}
previousContentOffset = currentContentOffset
print(currentContentOffset)
}
}
extension UIView {
public func addBlur(style: UIBlurEffect.Style = .extraLight) {
let blurEffect = UIBlurEffect(style: style)
let blurBackground = UIVisualEffectView(effect: blurEffect)
insertSubview(blurBackground, at: 0)
blurBackground.translatesAutoresizingMaskIntoConstraints = false
blurBackground.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
blurBackground.topAnchor.constraint(equalTo: topAnchor).isActive = true
blurBackground.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
blurBackground.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
}
@IBInspectable var cornerRadius: Double {
get {
return Double(self.layer.cornerRadius)
}set {
self.layer.cornerRadius = CGFloat(newValue)
}
}
@IBInspectable var makeCircle : Bool {
get {
return self.makeCircle
} set {
if newValue {
self.layer.cornerRadius=self.frame.height/2
} else {
self.layer.cornerRadius=0
}
}
}
func addShadow(offset: CGSize, color: UIColor, radius: CGFloat, opacity: Float) {
layer.masksToBounds = false
layer.shadowOffset = offset
layer.shadowColor = color.cgColor
layer.shadowRadius = radius
layer.shadowOpacity = opacity
let backgroundCGColor = backgroundColor?.cgColor
backgroundColor = nil
layer.backgroundColor = backgroundCGColor
}
}