檢測旋轉時的字體更改

Question

我有以下viewcontroller

class ViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {

@IBOutlet weak var collectionView: UICollectionView!

var dogs = ["Dog1", "Dog2","Dog3"]

override func viewDidLoad() {
    super.viewDidLoad()
    collectionView.delegate = self
    collectionView.dataSource = self
}

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return dogs.count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CustomCell", for: indexPath) as! CustomCell
     cell.testLabel.text = dogs[indexPath.row]
     return cell
}
}

以及以下的CustomCell

class CustomCell: UICollectionViewCell {

@IBOutlet weak var testLabel: UILabel!

override func awakeFromNib() {
    super.awakeFromNib()
    if (UIDevice.current.orientation == UIDeviceOrientation.portrait)
    {
       testLabel.font = UIFont(name: "HelveticaNeue-Bold", size: 10)
    }
    else
    {
        testLabel.font = UIFont(name: "HelveticaNeue-Italic", size: 25)
    }
   }
}

我在訪問viewcontroller時最初觀察字體更改，但在旋轉設備時沒有觀察到。例如，如果設備是portrait並且我訪問了viewcontroller ，我得到了正確的字體但是如果我將其更改為landscape ，它仍然顯示portrait字體。

類似地，如果我轉到另一個viewcontroller並在landscape訪問present viewcontroller ，它顯示正確的字體，當我將方向更改為portratit ，它仍然記住landscape字體。 我該如何糾正這個？

Answer 1

要解決您的問題，您應該在cellForItemAt設置testLabel font ，並且只需在旋轉更改時，您只需要為您的collectionView調用reloadData

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CustomCell", for: indexPath) as! CustomCell
    cell.testLabel.text = dogs[indexPath.row]
    if (UIDevice.current.orientation == UIDeviceOrientation.portrait)
    {
       cell.testLabel.font = UIFont(name: "HelveticaNeue-Bold", size: 10)
    }
    else
    {
        cell.testLabel.font = UIFont(name: "HelveticaNeue-Italic", size: 25)
    }
     return cell
}

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    YOUR_COLLECTION_VIEW.reloadData()
}