ios - 如何在自定义 UICollectionViewLayout 中仅允许垂直和水平滑动

Question

请帮我解决这个问题，我正在关注这个tutorial要制作自定义 UICollectionViewLayout，用户可以水平滑动以浏览各个部分，垂直滑动以显示项目。

我的问题是，我只希望用户在 UICollectionView 上垂直或水平滑动，而不是自由滑动。任何关于如何实现这一目标的想法将不胜感激。

这是代码

import UIKit

class moviesLayout: UICollectionViewLayout {

let CELL_HEIGHT = 307.0
let CELL_WIDTH  = 204.0

var cellAttrDict = Dictionary<NSIndexPath, UICollectionViewLayoutAttributes>()

var contentSize = CGSizeZero

var dataSourceDidUpdate = true

override func collectionViewContentSize() -> CGSize {

    return contentSize
}

override func prepareLayout() {

    if collectionView?.numberOfSections() > 0 {
        for section in 0...collectionView!.numberOfSections()-1 {
            if collectionView?.numberOfItemsInSection(section) > 0 {
                for item in 0...collectionView!.numberOfItemsInSection(section)-1 {
                            let cellIndex = NSIndexPath(forItem: item, inSection: section)
                            let xPos = Double(item) * CELL_WIDTH
                            let yPos = Double(section) * CELL_HEIGHT

                            var cellAttributes = UICollectionViewLayoutAttributes(forCellWithIndexPath: cellIndex)
                            cellAttributes.frame = CGRect(x: xPos, y: yPos, width: CELL_WIDTH, height: CELL_HEIGHT)
                            cellAttributes.zIndex = 1
                            cellAttrDict[cellIndex] = cellAttributes
                }
            }
        }
    }

    let contentWidth = Double(collectionView!.numberOfItemsInSection(0)) * CELL_WIDTH
    let contentHeight = Double(collectionView!.numberOfSections()) * CELL_HEIGHT
    self.contentSize = CGSize(width: contentWidth, height: contentHeight)

}

override func layoutAttributesForElementsInRect(rect: CGRect) -> [UICollectionViewLayoutAttributes]? {

    var attributesInRect = [UICollectionViewLayoutAttributes]()

    for cellAttributes in cellAttrDict.values {
        if CGRectIntersectsRect(rect, cellAttributes.frame) {
            attributesInRect.append(cellAttributes)
        }
    }

    return attributesInRect
}

override func layoutAttributesForItemAtIndexPath(indexPath: NSIndexPath) -> UICollectionViewLayoutAttributes? {
    return cellAttrDict[indexPath]!
}

override func shouldInvalidateLayoutForBoundsChange(newBounds: CGRect) -> Bool {
    return true
}

}

Answer 1

使用滑动手势识别器来触发方向变化的传统 flowLayout 怎么样？

var layout = UICollectionViewFlowLayout()

//Hook to two Swipe Gesture Recognizers - Up and Down
@IBAction func verticalSwipe(sender: AnyObject) {
    layout.scrollDirection = UICollectionViewScrollDirection.Vertical
    self.collectionView?.collectionViewLayout = layout
}

//Hook to two Swipe Gesture Recognizers - Left and Right    
@IBAction func horizontalSwipe(sender: AnyObject) {
    layout.scrollDirection = UICollectionViewScrollDirection.Horizontal
    self.collectionView?.collectionViewLayout = layout
}