ios - 以编程方式创建 UICollectionView(在 UIViewController 之外)

Question

我想创建一个 import UIKit 的子类

类AlbumPlayerProgressBar:UICollectionView稍后在xib中使用它。并且似乎无法弄清楚如何正确使用 init 函数

import UIKit

class AlbumPlayerProgressBar: UICollectionView, UICollectionViewDataSource {

    var progressBarType :ProgressBarType = .Player
    var numOfSlides: Int = 0
    var numOfPlayingSlide: Int = 0

    init()
    {
        super.init()

        self.register(UINib(nibName: NSStringFromClass(ProgressBarCell.self), bundle: nil), forCellWithReuseIdentifier: NSStringFromClass(ProgressBarCell.self))
    }


    func set(progressBarType :ProgressBarType, numOfSlides: Int, numOfPlayingSlide: Int) {

        self.progressBarType = progressBarType
        self.numOfSlides = numOfSlides
        self.numOfPlayingSlide = numOfPlayingSlide

        self.reloadData()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("AlbumPlayerProgressBar init(coder:) has not been implemented")
    }

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

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: NSStringFromClass(ProgressBarCell.self), for: indexPath) as! ProgressBarCell

        cell.setType(self.progressBarType)

        if (indexPath.row < numOfPlayingSlide)
        {
            cell.setPlayed()
        }
        else if (indexPath.row == numOfPlayingSlide)
        {
            cell.setPlaying()
        }
        else
        {
            cell.setUnplayed()
        }
        return cell
    }
}


enum ProgressBarType {
    case Player
    case Thumnail
}

Answer 1

您可以将 CollectionView 声明为

class AlbumPlayerProgressBar: UICollectionView, UICollectionViewDataSource {
    var progressBarType :ProgressBarType = .Player
    var numOfSlides: Int = 0
    var numOfPlayingSlide: Int = 0

    override func awakeFromNib() {
        super.awakeFromNib()
        //gets called when you instantiate your collectionView from xib
        self.register(UINib(nibName: NSStringFromClass(ProgressBarCell.self), bundle: nil), forCellWithReuseIdentifier: NSStringFromClass(ProgressBarCell.self))
        self.dataSource = self
    } 

    override init(frame: CGRect, collectionViewLayout layout: UICollectionViewLayout) {
        super.init(frame: frame, collectionViewLayout: layout)
        self.register(UINib(nibName: NSStringFromClass(ProgressBarCell.self), bundle: nil), forCellWithReuseIdentifier: NSStringFromClass(ProgressBarCell.self))
        self.dataSource = self
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.register(UINib(nibName: NSStringFromClass(ProgressBarCell.self), bundle: nil), forCellWithReuseIdentifier: NSStringFromClass(ProgressBarCell.self))
        self.dataSource = self
    }

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

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: NSStringFromClass(ProgressBarCell.self), for: indexPath) as! ProgressBarCell

        cell.setType(self.progressBarType)

        if (indexPath.row < numOfPlayingSlide)
        {
            cell.setPlayed()
        }
        else if (indexPath.row == numOfPlayingSlide)
        {
            cell.setPlaying()
        }
        else
        {
            cell.setUnplayed()
        }
        return cell
    }
}

根据您如何初始化/实例化collectionView来决定在哪里注册您的nib并将数据源设置为self。

希望对你有帮助