how to set dynamic height of a Collection View, the 'view' not the 'cells'?

Question

I have embedded a collection view in another view and disabled the collection view's scrolling ability, what i want to achieve is similar to Instagram's profile tab. However, I cannot figure out how should I set the height of the collection view in this case since the number of cells are dynamic.

I tried searching different solutions but most results are on changing the cells dynamically but not the collection view height itself. Is there any default/standard solutions for that?

Solution 1

Set the width you want the collection view to have (hopefully that is static), and request a layout:

collectionView.frame = CGRectMake(0., 0., width, 0.);
[collectionView layoutIfNeeded];

The calculated height of the collectionView will then be available at:

collectionView.contentSize.height

Solution 2

For Swift please follow below steps:

Declare a CGFloat variable in declaration section:

var height : CGFloat!

At viewDidAppear you can get it by:

height = self.myCollectionView.collectionViewLayout.collectionViewContentSize().height

Maybe when you reload data then need to calculate a new height with new data then you can get it by: addObserver to listen when your CollectionView finished reload data at viewWillAppear:

override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(true)
        ....
        ....
        self.shapeCollectionView.addObserver(self, forKeyPath: "contentSize", options: NSKeyValueObservingOptions.Old, context: nil)
    }

Then add bellow function to get new height or do anything after collectionview finished reload:

override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutablePointer<Void>) {
        let newHeight : CGFloat = self.myCollectionView.collectionViewLayout.collectionViewContentSize().height

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

        self.myCollectionView.frame = frame
    }

And don't forget to remove observer:

self.myCollectionView.removeObserver(self, forKeyPath: "contentSize")

I hope this will help you to solve your issue in swift.

Solution 3

1) you need to set height constraint to collectionview in storyboard or xibs

2) make outlet of heightConstraint

3) and use this code while relaod collectionview

collectionViewHeightConstaint.constant = collectionView.contentSize.height

Solution 4

Based on the fact you know the height of the cells and you know the number of cells on the screen. I would...

self.collectionView.frame = CGRectMake(0, 0, DEFINED_WIDTH, DEFINED_CELL_HEIGHT*Number of Cells);

or have I miss understood the question?

Solution 5

In your ViewController, set the frame of the collectionView. For example:

    self.collectionView.frame = CGRectMake(0, 0, 100, 200);

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Comments

[user3402639]

the height of the collection view is dynamic, depending the number of posts the user created, just like instagram, so i can't make it to constant....

[John]

Usually there is a dynamic number of cells. But if you really want a dynamic height of collectionView, you can set its frame whenever your datasource's array.count changes.

[Ravi Ojha]

i want to set the dynamic height of collection view, depend on the number of cells ,please tell me

[Er. Vihar]

@RaviJSS: Please check my answer below if you are working with swift. If you are working in objective-c then go through stackoverflow.com/a/28378625/6325474. This answer will help you a lot.