CODEWITHSUNDEEP
iphoneioscocoa-touchxamarin.ios
Jonas Sourlier
Jonas Sourlier

Reputation: 14465

UIViewController.View.Window is null in ViewDidLoad method

Regardless on which controller type (UIViewController, UITableViewController), the following line always yields null in the ViewDidLoad method:

this.View.Window

Is this behavior normal, or am I doing something odd? What could lead to UIViewController.View.Window being null?

(I suppose this question concerns not only MonoTouch, but also 'normal' Objective-C Cocoa).

(MonoTouch 5.2.11, Xcode 4.2.1 4D502)

Upvotes: 23

Views: 15088

Answers (4)

malhal
malhal

Reputation: 30729

If using UIScene you can get the window from viewWillAppear like this:

    func windowByParent(vc: UIViewController) -> UIWindow? {
        var window: UIWindow? = nil
        var parent: UIViewController? = vc
        
        while parent != nil && window == nil {
            window = parent?.view.window
            parent = parent?.parent
        }
        return window
    }

Upvotes: 0

dinesh sharma
dinesh sharma

Reputation: 617

self.view.window will be available in viewDidAppear:

override func viewDidAppear(_ animated: Bool) {
    print(self.view.window)
    let vc = self.storyboard?.instantiateViewController(identifier: "SecondViewController") as? SecondViewController
    self.view.window?.rootViewController = vc
}

Upvotes: 9

cprcrack
cprcrack

Reputation: 19169

Instead of self.view.window use 

[(YourAppDelegate *)[[UIApplication sharedApplication] delegate] window]

Upvotes: 5

sch
sch

Reputation: 27536

According to the documentation of UIView, the window property is nil if the view has not yet been added to a window which is the case when viewDidLoad is called.

Upvotes: 37

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