问题
I'm receiving notifications from Firebase in the AppDelegate class.
This notification contains a String named "notif_url". I've put this value in a var named "desired_url" and now I need to change my WebView url with the "desired_url" value.
But I can't access to the webview to change it url like this :
@IBOutlet weak var my_web_view: UIWebView!
func load_url(server_url: String){
let url = URL(string: server_url);
let request = URLRequest(url: url!);
my_web_view.loadRequest(request);
}
load_url(server_url: desired_url);
Do you know if I can do that and if yes, how ?
Images :
EDIT 1:
After adding breakPoint to know the wrong line, it seem't that the line is this one :
my_web_view.loadRequest(request)
EDIT 2:
If need, that's a part of my AppDelegate class code.
import UIKit
import UserNotifications
import Firebase
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
let gcmMessageIDKey = "gcm.message_id"
@IBOutlet weak var my_web_view: UIWebView!
func application(_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
return true
}
}
// [START ios_10_message_handling]
@available(iOS 10, *)
extension AppDelegate : UNUserNotificationCenterDelegate{
// Receive displayed notifications for iOS 10 devices.
func userNotificationCenter(_ center: UNUserNotificationCenter,
willPresent notification: UNNotification,
withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void){
print("Step : 12");
let userInfo = notification.request.content.userInfo
// Print message ID.
if let messageID = userInfo[gcmMessageIDKey]{
print("Message ID: \(messageID)")
}
// Print full message.
print(userInfo)
var url: String = userInfo[AnyHashable("url")] as! String;
load_url(server_url: url);
// Change this to your preferred presentation option
completionHandler([])
}
func load_url(server_url: String){
/*
let url = URL(string: server_url);
let request = URLRequest(url: url!);
my_web_view.loadRequest(request);
*/
guard let url = URL(string: server_url) else {
print("Invalid URL")
return
}
print("TRY : "+server_url);
let request = URLRequest(url: url)
my_web_view.loadRequest(request)
}
}
EDIT 3:
If need, that's my ViewController class code.
import Foundation
import UIKit
import SafariServices
import UserNotifications
class ViewController: UIViewController, UIWebViewDelegate{
@IBOutlet weak var my_web_view: UIWebView!
@IBOutlet weak var my_loading_view: UIView!
@IBOutlet weak var spinner : UIActivityIndicatorView!
@IBOutlet weak var app_logo : UIImageView!
@IBOutlet weak var deadlinePicker: UIDatePicker!
@IBOutlet weak var titleField: UITextField!
var new_url: String = "";
override func viewDidLoad(){
super.viewDidLoad()
let server_url = "https://www.sortirauhavre.com/";
NotificationCenter.default.addObserver(self, selector: #selector(self.rotated), name: NSNotification.Name.UIDeviceOrientationDidChange, object: nil)
rotated();
spinner.startAnimating();
my_web_view.scrollView.bounces = false;
my_web_view.scrollView.isScrollEnabled = true;
let url = URL(string: server_url);
let request = URLRequest(url: url!);
my_web_view.loadRequest(request);
}
// CETTE FONCITON SE LANCE A LA ROTATION DE L'APPAREIL
func rotated(){
app_logo.center = my_loading_view.center;
let y = app_logo.frame.origin.y;
let h = app_logo.frame.size.height
app_logo.frame.origin.y = y-(h/2);
spinner.center = my_loading_view.center;
}
// CETTE FONCTION MET EN ARRIERE PLAN L'ANNIMATION DE CHARGEMENT
func removeLoader(){
self.view.addSubview(my_web_view);
}
// CETTE FONCTION MET EN PREMIER PLAN L'ANNIMATION DE CHARGEMENT
func addLoader(){
self.view.addSubview(my_loading_view);
}
// CETTE FONCTION SE DECLANCHE QUAND LES PAGES DE LA WEBVIEW COMMENCE A CHANGER
func webViewDidStartLoad(_ webView: UIWebView){
addLoader();
let server_url = "https://www.sortirauhavre.com/";
_ = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(ViewController.removeLoader), userInfo: nil, repeats: false);
if let text = webView.request?.url?.absoluteString{
if text.hasPrefix(server_url){
}
else if text != ""{
UIApplication.shared.openURL(URL(string: text)!)
my_web_view.goBack()
}
}
}
// CETTE FONCTION SE DECLANCHE QUAND LES PAGES DE LA WEBVIEW FINI DE CHANGER
func webViewDidFinishLoad(_ webView: UIWebView){
let server_url = "https://www.sortirauhavre.com/";
_ = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(ViewController.removeLoader), userInfo: nil, repeats: false);
if let text = webView.request?.url?.absoluteString{
if text.hasPrefix(server_url){
}
else if text != ""{
UIApplication.shared.openURL(URL(string: text)!)
my_web_view.goBack()
}
}
}
}
回答1:
You are force unwrapping url which is not a valid URL. I would suggest adding a guard statement to prevent the crash if a invalid URL is created:
func load_url(server_url: String) {
guard let url = URL(string: server_url) else {
print("Invalid URL")
return
}
let request = URLRequest(url: url)
my_web_view.loadRequest(request)
}
As you are obtaining the URL in the AppDelegate you cannot simply update the UIWebView from this class. You will need to call a function in the my_web_view's parent class which updates the URL.
// App Delegate
var serverURL: String?
func load_url(server_url: String) {
serverURL = server_url
let notificationName = Notification.Name("updateWebView")
NotificationCenter.default.post(name: notificationName, object: nil)
}
// View Controller
override func viewDidLoad() {
let notificationName = Notification.Name("updateWebView")
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.updateWebView), name: notificationName, object: nil)
updateWebView()
}
func updateWebView() {
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let serverURL = appDelegate.serverURL
guard let url = URL(string: serverURL) else {
print("Invalid URL")
return
}
let request = URLRequest(url: URL)
my_web_view.loadRequest(request)
}
回答2:
Instead of creating a new instance of your view controller, or trying to duplicate the outlet, you just need to access the current instance of your view controller. You can use either:
- A global value for the view controller, or
- A singleton-like pattern.
Then you can access the instance from your app delegate, by calling either myGlobalViewController.webView or ViewController.instance.webView.
So, here's an example:
import UIKit
private var thisViewController: ViewController? // Will hold the instance.
class ViewController: UIViewController {
static var instance: ViewController {
guard let thisViewController = thisViewController else { fatalError() } // Don't do this unless you're 100% sure that you'll never access this before the instance is loaded.
return thisViewController
}
@IBOutlet weak var webView: UIWebView!
override func viewDidLoad() {
super.viewDidLoad()
thisViewController = self // Set the property to self.
}
...
}
After this, you can access the web view from your app delegate:
func load_url(server_url: String){
guard let url = URL(string: server_url) else {
return
}
let request = URLRequest(url: url)
ViewController.instance.webView.loadRequest(request)
}
来源：https://stackoverflow.com/questions/43408531/change-webview-url-from-appdelegate