设置 layer.borderColor 时 UICollectionViewCell 边框消失

Question

我正在尝试向 @IBDesignable UICollectionViewCell 原型添加细的彩色边框。在 Storyboard 中，我设置了 layer.cornerRadius、layer.masksToBounds 和 layer.borderWidth 用户定义属性，边框按预期显示。

但是，如果我还设置自定义 layer.borderColor，整个边框、半径和遮罩将从故事板中消失。在模拟器中，角半径（和掩码，大概）出现，但边界没有。

我也尝试过以编程方式设置它们，但正如 this year-old, unanswered Whosebug question 所示，这也不起作用。

根据要求，这是单元格的代码：

@IBDesignable open class ReleaseSpineCell: UICollectionViewCell {

    public var masterRelease: MasterRelease? {
        didSet {
            artistName = masterRelease?.artistName
            title = masterRelease?.title
            catalogNumber = "none"
        }
    }

    @IBInspectable public var artistName: String? {
        didSet {
            artistLabel?.text = artistName
        }
    }

    @IBInspectable public var title: String? {
        didSet {
            titleLabel?.text = title
        }
    }

    @IBInspectable public var catalogNumber: String? {
        didSet {
            catalogLabel?.text = catalogNumber
        }
    }

    @IBOutlet private weak var artistLabel: UILabel?
    @IBOutlet private weak var titleLabel: UILabel?
    @IBOutlet private weak var catalogLabel: UILabel?

}

以及 UICollectionViewController 的 dataSource 的相关部分：

class CollectionModel: FetchedResultsCollectionModel {

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "spineCell", for: indexPath) as! ReleaseSpineCell
        cell.masterRelease = fetchedResultsController?.fetchedObjects?[indexPath.row] as? MasterRelease

        return cell
    }
}

FetchedResultsCollectionModel 是由 NSFetchedResultsController 支持的自定义集合视图数据源和委托，MasterRelease 是托管对象。我尽量让这些东西尽可能简单。

Answer 1

您面临的问题是您正在使用 Boolean 值 layer.borderColor，您必须改用 Color。但无论如何这不起作用，因为对于 layer.borderColor 你需要一个 cgColor 所以我认为你需要为 borderColor 定义一个 @IBInspectable var 并在代码中执行此操作

@IBDesignable open class ReleaseSpineCell: UICollectionViewCell {

    public var masterRelease: MasterRelease? {
        didSet {
            artistName = masterRelease?.artistName
            title = masterRelease?.title
            catalogNumber = "none"
        }
    }

    @IBInspectable public var artistName: String? {
        didSet {
            artistLabel?.text = artistName
        }
    }

    @IBInspectable public var title: String? {
        didSet {
            titleLabel?.text = title
        }
    }

    @IBInspectable public var catalogNumber: String? {
        didSet {
            catalogLabel?.text = catalogNumber
        }
    }

    //added this inspectable property
    @IBInspectable public var borderColor: UIColor? {
        didSet {
            self.layer.borderColor = borderColor!.cgColor
        }
    }

    @IBOutlet private weak var artistLabel: UILabel?
    @IBOutlet private weak var titleLabel: UILabel?
    @IBOutlet private weak var catalogLabel: UILabel?

}

然后你就可以在情节提要中做到这一点

希望对您有所帮助

设置 layer.borderColor 时 UICollectionViewCell 边框消失

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