CODEWITHSUNDEEP
iosswiftxcode
Shikha Sharma
Shikha Sharma

Reputation: 469

Error : An -observeValueForKeyPath:ofObject:change:context: message was received but not handled

I want to set height of collection view dynamic according to content, I tried below code :

    override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(true)

    self.ItemCollection.addObserver(self , forKeyPath: "contentSize", options: NSKeyValueObservingOptions.old, context: nil)


}


func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutableRawPointer) {

    let newHeight : CGFloat = self.ItemCollection.collectionViewLayout.collectionViewContentSize.height

    var frame : CGRect! = self.ItemCollection.frame
    frame.size.height = newHeight

    self.ItemCollection.frame = frame


}    

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(true)

            self.ItemCollection.removeObserver(self, forKeyPath: "contentSize")
}

I'm getting error on this line :

 self.ItemCollection.addObserver(self , forKeyPath: "contentSize", options: NSKeyValueObservingOptions.old, context: nil)

Below is the error :

An -observeValueForKeyPath:ofObject:change:context: message was received but not handled.
Key path: contentSize
Observed object: <UICollectionView: 0x102911200; frame = (0 275; 375 360);     clipsToBounds = YES; autoresize = W+TM+H+BM; gestureRecognizers = <NSArray: 0x1c4247a40>; layer = <CALayer: 0x1c02388a0>; contentOffset: {0, 0}; contentSize: {375, 0}; adjustedContentInset: {0, 0, 0, 0}> collection view layout: <UICollectionViewFlowLayout: 0x102543a80>
Change: {
kind = 1;
old = "NSSize: {20, 360}";
}
Context: 0x0'

Upvotes: 1

Views: 1143

Answers (1)

Tj3n
Tj3n

Reputation: 9923

In Swift 4, Its an override function, should be -

override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?)

Upvotes: 8

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