代码：
import UIKit class CustomCollectionViewLayout: UICollectionViewLayout { // let numberOfColumns = 8 var numberOfColumns = 8 var itemAttributes : NSMutableArray! var itemsSize : NSMutableArray! var contentSize : CGSize! override func layoutAttributesForItemAtIndexPath(indexPath: NSIndexPath) -> UICollectionViewLayoutAttributes? { return self.itemAttributes[indexPath.section][indexPath.row] as? UICollectionViewLayoutAttributes } |
出错：
CustomCollectionViewLayout.swift:117:35: Ambiguous use of ‘subscript’
Found this candidate (Foundation.NSArray)
Found this candidate (Metal.MTLRenderPassColorAttachmentDescriptorArray)
Found this candidate (Metal.MTLRenderPipelineColorAttachmentDescriptorArray)
Found this candidate (Metal.MTLVertexBufferLayoutDescriptorArray)
Found this candidate (Metal.MTLVertexAttributeDescriptorArray)
如图：
swift Ambiguous use of subscript
swift2 – Ambiguous use of ‘subscript’ – ios 9 Swift 2.0 – Stack Overflow
去改为：
override func layoutAttributesForItemAtIndexPath(indexPath: NSIndexPath) -> UICollectionViewLayoutAttributes? { //return self.itemAttributes[indexPath.section][indexPath.row] as? UICollectionViewLayoutAttributes let sectionAttributes = self.itemAttributes[indexPath.section] as! [UICollectionViewLayoutAttributes] return sectionAttributes[indexPath.row] as UICollectionViewLayoutAttributes } |
即可。
－》更好的做好其实是：
在定义的时候，就定义清楚：
//var itemAttributes : NSMutableArray! var itemAttributes : [[UICollectionViewLayoutAttributes]]! |
但是对于：
if (self.itemAttributes == nil) { self.itemAttributes = NSMutableArray(capacity: self.collectionView!.numberOfSections()) } |
会报错：
/CustomCollectionViewLayout.swift:105:39: Cannot assign value of type ‘NSMutableArray’ to type ‘[[UICollectionViewLayoutAttributes]]!’
－》算了，懒得研究了。放弃。
另外，该文件也存在一些语法的警告，最终改为：
// // CustomCollectionViewLayout.swift // CustomCollectionLayout // // Created by JOSE MARTINEZ on 15/12/2014. // Copyright (c) 2014 brightec. All rights reserved. // import UIKit class CustomCollectionViewLayout: UICollectionViewLayout { // let numberOfColumns = 8 var numberOfColumns = 8 var itemAttributes : NSMutableArray! // var itemAttributes : [[UICollectionViewLayoutAttributes]]! var itemsSize : NSMutableArray! var contentSize : CGSize! override func prepareLayout() { if self.collectionView?.numberOfSections() == 0 { return } if (self.itemAttributes != nil && self.itemAttributes.count > 0) { for section in 0..<self.collectionView!.numberOfSections() { let numberOfItems : Int = self.collectionView!.numberOfItemsInSection(section) for index in 0..<numberOfItems { if section != 0 && index != 0 { continue } let attributes : UICollectionViewLayoutAttributes = self.layoutAttributesForItemAtIndexPath(NSIndexPath(forItem: index, inSection: section))! if section == 0 { var frame = attributes.frame frame.origin.y = self.collectionView!.contentOffset.y attributes.frame = frame } if index == 0 { var frame = attributes.frame frame.origin.x = self.collectionView!.contentOffset.x attributes.frame = frame } } } return } if (self.itemsSize == nil || self.itemsSize.count != numberOfColumns) { self.calculateItemsSize() } var column = 0 var xOffset : CGFloat = 0 var yOffset : CGFloat = 0 var contentWidth : CGFloat = 0 var contentHeight : CGFloat = 0 for section in 0..<self.collectionView!.numberOfSections() { //let sectionAttributes = NSMutableArray() var sectionAttributes = [UICollectionViewLayoutAttributes]() for index in 0..<numberOfColumns { let itemSize = self.itemsSize[index].CGSizeValue() let indexPath = NSIndexPath(forItem: index, inSection: section) let attributes = UICollectionViewLayoutAttributes(forCellWithIndexPath: indexPath) attributes.frame = CGRectIntegral(CGRectMake(xOffset, yOffset, itemSize.width, itemSize.height)) if section == 0 && index == 0 { attributes.zIndex = 1024; } else if section == 0 || index == 0 { attributes.zIndex = 1023 } if section == 0 { var frame = attributes.frame frame.origin.y = self.collectionView!.contentOffset.y attributes.frame = frame } if index == 0 { var frame = attributes.frame frame.origin.x = self.collectionView!.contentOffset.x attributes.frame = frame } //sectionAttributes.addObject(attributes) sectionAttributes.append(attributes) xOffset += itemSize.width column += 1 if column == numberOfColumns { if xOffset > contentWidth { contentWidth = xOffset } column = 0 xOffset = 0 yOffset += itemSize.height } } if (self.itemAttributes == nil) { self.itemAttributes = NSMutableArray(capacity: self.collectionView!.numberOfSections()) // self.itemAttributes = Array<Array<UICollectionViewLayoutAttributes>>() // self.itemAttributes = [[UICollectionViewLayoutAttributes]]() } self.itemAttributes.addObject(sectionAttributes) // self.itemAttributes.append(sectionAttributes) } let attributes : UICollectionViewLayoutAttributes = self.itemAttributes.lastObject?.lastObject as! UICollectionViewLayoutAttributes contentHeight = attributes.frame.origin.y + attributes.frame.size.height self.contentSize = CGSizeMake(contentWidth, contentHeight) } override func collectionViewContentSize() -> CGSize { return self.contentSize } override func layoutAttributesForItemAtIndexPath(indexPath: NSIndexPath) -> UICollectionViewLayoutAttributes? { //return self.itemAttributes[indexPath.section][indexPath.row] as? UICollectionViewLayoutAttributes let sectionAttributes = self.itemAttributes[indexPath.section] as! [UICollectionViewLayoutAttributes] return sectionAttributes[indexPath.row] as UICollectionViewLayoutAttributes } override func layoutAttributesForElementsInRect(rect: CGRect) -> [UICollectionViewLayoutAttributes]? { var attributes = [UICollectionViewLayoutAttributes]() if self.itemAttributes != nil { for section in self.itemAttributes { let filteredArray = section.filteredArrayUsingPredicate( NSPredicate(block: { (evaluatedObject, bindings) -> Bool in return CGRectIntersectsRect(rect, evaluatedObject.frame) }) ) as! [UICollectionViewLayoutAttributes] attributes.appendContentsOf(filteredArray) } } return attributes } override func shouldInvalidateLayoutForBoundsChange(newBounds: CGRect) -> Bool { return true } func sizeForItemWithColumnIndex(columnIndex: Int) -> CGSize { var text : String = “” switch (columnIndex) { case 0: text = “Col 0” case 1: text = “Col 1” case 2: text = “Col 2” case 3: text = “Col 3” case 4: text = “Col 4” case 5: text = “Col 5” case 6: text = “Col 6” default: text = “Col 7” } let size : CGSize = (text as NSString).sizeWithAttributes([NSFontAttributeName: UIFont.systemFontOfSize(17.0)]) let width : CGFloat = size.width + 25 return CGSizeMake(width, 30) } func calculateItemsSize() { self.itemsSize = NSMutableArray(capacity: numberOfColumns) for index in 0..<numberOfColumns { self.itemsSize.addObject(NSValue(CGSize: self.sizeForItemWithColumnIndex(index))) } } } |