UICollectionViewのヘッダーについて
UICollectionViewを使ってセクションが複数ある画面を実装しています。
セルの大きさを可変にするため、UICollectionViewFlowLayoutをカスタムして利用しています。
ヘッダーを表示するには、レイアウトを生成した際に以下の値を設定する認識です。
let layout = UICollectionViewFlowLayout()
layout.headerReferenceSize = CGSizeMake(10,10)
上記を設定することで、以下のファンクションが呼ばれる認識です。
func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {}
以下のようにレイアウトにカスタムクラスを利用した際、上記のファンクションが呼ばれなくなってしまいました。
let layout = CustomLayout()
layout.headerReferenceSize = CGSizeMake(10,10)
どこかでheaderReferenceSizeの値がクリアされてしまう等、何か原因がありますでしょうか？
ViewController.swift
var myCollectionView : UICollectionView!
var mySection: [String] = [“セクション１”,”セクション２”]
override func viewDidLoad() {
super.viewDidLoad()
let layout = CustomLayout()
// セクション毎のヘッダーサイズ
layout.headerReferenceSize = CGSizeMake(self.view.frame.width, 100)
layout.sectionInset = UIEdgeInsetsMake(8, 8, 8, 8)
layout.minimumLineSpacing = 8
layout.minimumInteritemSpacing = 8
layout.maxColumn = 5
layout.cellPattern.append((sideLength: 2,heightLength: 2,column: 0,row: 0))
layout.cellPattern.append((sideLength: 1,heightLength: 1,column: 2,row: 0))
layout.cellPattern.append((sideLength: 1,heightLength: 1,column: 3,row: 0))
layout.cellPattern.append((sideLength: 1,heightLength: 1,column: 4,row: 0))
layout.cellPattern.append((sideLength: 1,heightLength: 1,column: 2,row: 1))
layout.cellPattern.append((sideLength: 1,heightLength: 1,column: 3,row: 1))
layout.cellPattern.append((sideLength: 1,heightLength: 1,column: 4,row: 1))
myCollectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
myCollectionView.registerClass(CustomUICollectionViewCell.self, forCellWithReuseIdentifier: "MyCell")
myCollectionView.registerClass(CustomCollectionReusableView.self, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "MySection")
myCollectionView.delegate = self
myCollectionView.dataSource = self
self.view.addSubview(myCollectionView)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return mySection.count
}
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
print(“セル押下”)
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
switch (section) {
case 0:
return 7
case 1:
return 7
default:
return 0
}
}
func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
let headerView: CustomCollectionReusableView = collectionView.dequeueReusableSupplementaryViewOfKind(UICollectionElementKindSectionHeader, withReuseIdentifier: "MySection", forIndexPath: indexPath) as! CustomCollectionReusableView
headerView.title?.text = mySection[indexPath.section]
return headerView
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell: CustomUICollectionViewCell = collectionView.dequeueReusableCellWithReuseIdentifier("MyCell", forIndexPath: indexPath) as! CustomUICollectionViewCell
switch (indexPath.section) {
case 0:
cell.backgroundColor = UIColor.redColor()
cell.textLabel?.text = "0"
cell.imageTest.image = UIImage(named: "image01.jpg")
case 1:
cell.backgroundColor = UIColor.greenColor()
cell.textLabel?.text = "1"
default:
print("section error")
cell.backgroundColor = UIColor.whiteColor()
}
return cell
}
CustomUICollectionViewCell.swift
var textLabel: UILabel!
var imageTest: UIImageView!
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override init(frame: CGRect) {
super.init(frame: frame)
textLabel = UILabel(frame: CGRectMake(0,0,frame.width,frame.height))
textLabel?.text = "nil"
textLabel?.textAlignment = NSTextAlignment.Center
imageTest = UIImageView(frame: CGRectMake(0,0,frame.width,frame.height))
self.contentView.addSubview(imageTest)
self.contentView.addSubview(textLabel)
}
CustomLayout.swift
private static let maxRow = 3
var maxColumn = maxRow
var cellPattern:[(sideLength: CGFloat, heightLength: CGFloat, column: CGFloat, row:CGFloat)] = []
private var sectionCells = [[CGRect]]()
private var contentSize = CGSizeZero
override func prepareLayout() {
super.prepareLayout()
sectionCells = [[CGRect]]()
if let collectionView = self.collectionView {
contentSize = CGSize(width: collectionView.bounds.width - collectionView.contentInset.left - collectionView.contentInset.right, height: 0)
let smallCellSideLength: CGFloat = (contentSize.width - super.sectionInset.left - super.sectionInset.right - (super.minimumInteritemSpacing * (CGFloat(maxColumn) - 1.0))) / CGFloat(maxColumn)
for section in (0..<collectionView.numberOfSections()) {
var cells = [CGRect]()
let numberOfCellInSection = collectionView.numberOfItemsInSection(section)
var height = contentSize.height
for i in (0..<numberOfCellInSection) {
let position = i % (numberOfCellInSection)
let cellPosition = position % cellPattern.count
let cell = cellPattern[cellPosition]
let x = (cell.column * (smallCellSideLength + super.minimumInteritemSpacing)) + super.sectionInset.left
let y = (cell.row * (smallCellSideLength + super.minimumLineSpacing)) + contentSize.height + super.sectionInset.top
let cellwidth = (cell.sideLength * smallCellSideLength) + ((cell.sideLength-1) * super.minimumInteritemSpacing)
let cellheight = (cell.heightLength * smallCellSideLength) + ((cell.heightLength-1) * super.minimumInteritemSpacing)
let cellRect = CGRectMake(x, y, cellwidth, cellheight)
cells.append(cellRect)
if (height < cellRect.origin.y + cellRect.height ) {
height = cellRect.origin.y + cellRect.height
}
}
contentSize = CGSize(width: contentSize.width, height: height)
sectionCells.append(cells)
}
}
}
override func layoutAttributesForElementsInRect(rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
var layoutAttributes = [UICollectionViewLayoutAttributes]()
if let collectionView = self.collectionView {
for i in (0..<collectionView.numberOfSections()) {
let numberOfCellsInSection = collectionView.numberOfItemsInSection(i)
for j in (0..<numberOfCellsInSection) {
let indexPath = NSIndexPath(forRow: j, inSection: i)
if let attributes = layoutAttributesForItemAtIndexPath(indexPath) {
if (CGRectIntersectsRect(rect, attributes.frame)) {
layoutAttributes.append(attributes)
}
}
}
}
}
return layoutAttributes
}
override func layoutAttributesForItemAtIndexPath(indexPath: NSIndexPath) -> UICollectionViewLayoutAttributes? {
let attributes = super.layoutAttributesForItemAtIndexPath(indexPath)
attributes!.frame = sectionCells[indexPath.section][indexPath.row]
return attributes
}
override func collectionViewContentSize() -> CGSize {
return contentSize
}
CustomCollectionReusableView.swift
var title: UILabel!
var backgroundImage: UIImageView!
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override init(frame: CGRect) {
super.init(frame: frame)
title = UILabel(frame: CGRectMake(frame.width*0.05,0,frame.width,frame.height))
title.text = "nil"
title.textAlignment = NSTextAlignment.Left
title.textColor = UIColor.redColor()
let bgImage: UIImage = UIImage(named: "image02.jpg")!
backgroundImage = UIImageView(frame: CGRectMake(0, 0, frame.width, frame.height))
backgroundImage.image = bgImage
self.addSubview(backgroundImage)
self.addSubview(title)
}