曖昧參考成員「下標」 SWIFT 3

Question

我想創建一個UICollectionViewFlowLayout子和我收到曖昧參考成員「下標」錯誤，當我嘗試返回layoutAttributesForItem： 進口的UIKit

class FLCollectionViewFlowLayout: UICollectionViewFlowLayout { 

    var items = 0 
    let CELL_HEIGHT : CGFloat = 306.0 
    let CELL_WIDTH : CGFloat = 219.0 
    var cellInformation = Dictionary<NSIndexPath,UICollectionViewLayoutAttributes>() 
    var contentSize = CGSize.zero 

    override var collectionViewContentSize: CGSize { 
     return self.contentSize 
    } 

    override func prepare() { 
     super.prepare() 
     print("preparing layout") 
     items = 20 
     let sections = self.collectionView?.numberOfSections 
     var section = 0 
     var item = 0 
     var indexPath = NSIndexPath() 
     var contentWidth : CGFloat = 0.0 
     let contentHeight : CGFloat = CELL_HEIGHT + self.sectionInset.top + self.sectionInset.bottom 
     while section < sections! { 
      while item < (self.collectionView?.numberOfItems(inSection: section))! { 
       indexPath = NSIndexPath(item: item, section: section) 
       let xPos = CGFloat(item) * CELL_WIDTH 
       let yPos = CGFloat(section) * CELL_HEIGHT 
       let cellAttributes = UICollectionViewLayoutAttributes(forCellWith: indexPath as IndexPath) 
       cellAttributes.frame = CGRect(x: xPos, y: yPos, width: CELL_WIDTH, height: CELL_HEIGHT) 
       cellInformation[indexPath] = cellAttributes 
       item+=1 
      } 
      contentWidth = CGFloat((self.collectionView?.numberOfItems(inSection:section))!) * CELL_WIDTH 
      section+=1 
     } 
     self.contentSize = CGSize(width: contentWidth, height: contentHeight) 

    } 

    override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? { 
     var attributesInRect = [UICollectionViewLayoutAttributes]() 

     for cellAttributes in cellInformation.values { 
      if rect.intersects(cellAttributes.frame) { 
       attributesInRect.append(cellAttributes) 
      } 
     } 

     return attributesInRect 
    } 

    override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? { 

     return cellInformation[indexPath]! // <---- This is where i get the error 

    } 

} 

任何建議將不勝感激。

Answer 1

在斯威夫特3 NSIndexPath已被替換成原生結構IndexPath

變化

... 
var cellInformation = Dictionary<IndexPath,UICollectionViewLayoutAttributes>() 
... 
var indexPath = IndexPath() 
... 
indexPath = IndexPath(item: item, section: section) 
... 
let cellAttributes = UICollectionViewLayoutAttributes(forCellWith: indexPath)