방금 UICollectionViews에 대해 배우기 시작했습니다. 누구나 collectionview에서 열 수를 지정하는 방법을 알고 있는지 궁금합니다. 기본값은 3 (iPhone / 세로)입니다. 문서를 살펴본 결과 간결한 답을 찾을 수없는 것 같습니다.
답변
CollectionView는 매우 강력하며 대가가 따릅니다. 많은 옵션. omz가 말했듯이 :
열 수를 변경할 수있는 여러 가지 방법이 있습니다.
<UICollectionViewDelegateFlowLayout>프로토콜을 구현하여 UICollectionView서브 클래 싱 할 필요없이 .NET의 레이아웃을 더 잘 제어 할 수있는 다음 메서드에 대한 액세스를 제공 하는 것이 좋습니다 .
collectionView:layout:insetForSectionAtIndex:collectionView:layout:minimumInteritemSpacingForSectionAtIndex:collectionView:layout:minimumLineSpacingForSectionAtIndex:collectionView:layout:referenceSizeForFooterInSection:collectionView:layout:referenceSizeForHeaderInSection:collectionView:layout:sizeForItemAtIndexPath:
또한 다음 메서드를 구현하면 UICollectionView가 방향 변경시 레이아웃을 업데이트하도록 강제합니다 (예 : 가로로 셀의 크기를 조정하고 늘 이도록하려는 경우).
-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation
duration:(NSTimeInterval)duration{
[self.myCollectionView.collectionViewLayout invalidateLayout];
}또한 다음과 같은 2 개의 정말 좋은 튜토리얼이 있습니다 UICollectionViews.
http://www.raywenderlich.com/22324/beginning-uicollectionview-in-ios-6-part-12
http://skeuo.com/uicollectionview-custom-layout-tutorial
답변
Swift 5 및 iOS 12.3에서는 삽입 및 크기 변경 (회전 포함)을 관리하면서 행당 항목 수를 설정하기 위해 다음 4 가지 구현 중 하나를 사용할 수 있습니다 UICollectionView.
#1. 의 속성 서브 클래 싱 UICollectionViewFlowLayout및 사용UICollectionViewFlowLayoutitemSize
ColumnFlowLayout.swift :
import UIKit
class ColumnFlowLayout: UICollectionViewFlowLayout {
let cellsPerRow: Int
init(cellsPerRow: Int, minimumInteritemSpacing: CGFloat = 0, minimumLineSpacing: CGFloat = 0, sectionInset: UIEdgeInsets = .zero) {
self.cellsPerRow = cellsPerRow
super.init()
self.minimumInteritemSpacing = minimumInteritemSpacing
self.minimumLineSpacing = minimumLineSpacing
self.sectionInset = sectionInset
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func prepare() {
super.prepare()
guard let collectionView = collectionView else { return }
let marginsAndInsets = sectionInset.left + sectionInset.right + collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right + minimumInteritemSpacing * CGFloat(cellsPerRow - 1)
let itemWidth = ((collectionView.bounds.size.width - marginsAndInsets) / CGFloat(cellsPerRow)).rounded(.down)
itemSize = CGSize(width: itemWidth, height: itemWidth)
}
override func invalidationContext(forBoundsChange newBounds: CGRect) -> UICollectionViewLayoutInvalidationContext {
let context = super.invalidationContext(forBoundsChange: newBounds) as! UICollectionViewFlowLayoutInvalidationContext
context.invalidateFlowLayoutDelegateMetrics = newBounds.size != collectionView?.bounds.size
return context
}
}CollectionViewController.swift :
import UIKit
class CollectionViewController: UICollectionViewController {
let columnLayout = ColumnFlowLayout(
cellsPerRow: 5,
minimumInteritemSpacing: 10,
minimumLineSpacing: 10,
sectionInset: UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
)
override func viewDidLoad() {
super.viewDidLoad()
collectionView?.collectionViewLayout = columnLayout
collectionView?.contentInsetAdjustmentBehavior = .always
collectionView?.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 59
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
cell.backgroundColor = UIColor.orange
return cell
}
}
# 2. 사용 UICollectionViewFlowLayout의 itemSize방법을
import UIKit
class CollectionViewController: UICollectionViewController {
let margin: CGFloat = 10
let cellsPerRow = 5
override func viewDidLoad() {
super.viewDidLoad()
guard let collectionView = collectionView, let flowLayout = collectionViewLayout as? UICollectionViewFlowLayout else { return }
flowLayout.minimumInteritemSpacing = margin
flowLayout.minimumLineSpacing = margin
flowLayout.sectionInset = UIEdgeInsets(top: margin, left: margin, bottom: margin, right: margin)
collectionView.contentInsetAdjustmentBehavior = .always
collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
}
override func viewWillLayoutSubviews() {
guard let collectionView = collectionView, let flowLayout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout else { return }
let marginsAndInsets = flowLayout.sectionInset.left + flowLayout.sectionInset.right + collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right + flowLayout.minimumInteritemSpacing * CGFloat(cellsPerRow - 1)
let itemWidth = ((collectionView.bounds.size.width - marginsAndInsets) / CGFloat(cellsPerRow)).rounded(.down)
flowLayout.itemSize = CGSize(width: itemWidth, height: itemWidth)
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 59
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
cell.backgroundColor = UIColor.orange
return cell
}
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
collectionView?.collectionViewLayout.invalidateLayout()
super.viewWillTransition(to: size, with: coordinator)
}
}#삼. 사용 UICollectionViewDelegateFlowLayout의 collectionView(_:layout:sizeForItemAt:)방법을
import UIKit
class CollectionViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
let inset: CGFloat = 10
let minimumLineSpacing: CGFloat = 10
let minimumInteritemSpacing: CGFloat = 10
let cellsPerRow = 5
override func viewDidLoad() {
super.viewDidLoad()
collectionView?.contentInsetAdjustmentBehavior = .always
collectionView?.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: inset, left: inset, bottom: inset, right: inset)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return minimumLineSpacing
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return minimumInteritemSpacing
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let marginsAndInsets = inset * 2 + collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right + minimumInteritemSpacing * CGFloat(cellsPerRow - 1)
let itemWidth = ((collectionView.bounds.size.width - marginsAndInsets) / CGFloat(cellsPerRow)).rounded(.down)
return CGSize(width: itemWidth, height: itemWidth)
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 59
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
cell.backgroundColor = UIColor.orange
return cell
}
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
collectionView?.collectionViewLayout.invalidateLayout()
super.viewWillTransition(to: size, with: coordinator)
}
}# 4. 의 속성 서브 클래 싱 UICollectionViewFlowLayout및 사용UICollectionViewFlowLayoutestimatedItemSize
CollectionViewController.swift :
import UIKit
class CollectionViewController: UICollectionViewController {
let items = [
"Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
"Lorem ipsum dolor sit amet, consectetur.",
"Lorem ipsum dolor sit amet.",
"Lorem ipsum dolor sit amet, consectetur.",
"Lorem ipsum dolor sit amet, consectetur adipiscing.",
"Lorem ipsum.",
"Lorem ipsum dolor sit amet.",
"Lorem ipsum dolor sit.",
"Lorem ipsum dolor sit amet, consectetur adipiscing.",
"Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor.",
"Lorem ipsum dolor sit amet, consectetur."
]
let columnLayout = FlowLayout(
cellsPerRow: 3,
minimumInteritemSpacing: 10,
minimumLineSpacing: 10,
sectionInset: UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
)
override func viewDidLoad() {
super.viewDidLoad()
collectionView?.collectionViewLayout = columnLayout
collectionView?.contentInsetAdjustmentBehavior = .always
collectionView?.register(Cell.self, forCellWithReuseIdentifier: "Cell")
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return items.count
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! Cell
cell.label.text = items[indexPath.row]
return cell
}
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
collectionView?.collectionViewLayout.invalidateLayout()
super.viewWillTransition(to: size, with: coordinator)
}
}FlowLayout.swift :
import UIKit
class FlowLayout: UICollectionViewFlowLayout {
let cellsPerRow: Int
required init(cellsPerRow: Int = 1, minimumInteritemSpacing: CGFloat = 0, minimumLineSpacing: CGFloat = 0, sectionInset: UIEdgeInsets = .zero) {
self.cellsPerRow = cellsPerRow
super.init()
self.minimumInteritemSpacing = minimumInteritemSpacing
self.minimumLineSpacing = minimumLineSpacing
self.sectionInset = sectionInset
estimatedItemSize = UICollectionViewFlowLayout.automaticSize
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
guard let layoutAttributes = super.layoutAttributesForItem(at: indexPath) else { return nil }
guard let collectionView = collectionView else { return layoutAttributes }
let marginsAndInsets = collectionView.safeAreaInsets.left + collectionView.safeAreaInsets.right + sectionInset.left + sectionInset.right + minimumInteritemSpacing * CGFloat(cellsPerRow - 1)
layoutAttributes.bounds.size.width = ((collectionView.bounds.width - marginsAndInsets) / CGFloat(cellsPerRow)).rounded(.down)
return layoutAttributes
}
override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
let superLayoutAttributes = super.layoutAttributesForElements(in: rect)!.map { $0.copy() as! UICollectionViewLayoutAttributes }
guard scrollDirection == .vertical else { return superLayoutAttributes }
let layoutAttributes = superLayoutAttributes.compactMap { layoutAttribute in
return layoutAttribute.representedElementCategory == .cell ? layoutAttributesForItem(at: layoutAttribute.indexPath) : layoutAttribute
}
// (optional) Uncomment to top align cells that are on the same line
/*
let cellAttributes = layoutAttributes.filter({ $0.representedElementCategory == .cell })
for (_, attributes) in Dictionary(grouping: cellAttributes, by: { ($0.center.y / 10).rounded(.up) * 10 }) {
guard let max = attributes.max(by: { $0.size.height < $1.size.height }) else { continue }
for attribute in attributes where attribute.size.height != max.size.height {
attribute.frame.origin.y = max.frame.origin.y
}
}
*/
// (optional) Uncomment to bottom align cells that are on the same line
/*
let cellAttributes = layoutAttributes.filter({ $0.representedElementCategory == .cell })
for (_, attributes) in Dictionary(grouping: cellAttributes, by: { ($0.center.y / 10).rounded(.up) * 10 }) {
guard let max = attributes.max(by: { $0.size.height < $1.size.height }) else { continue }
for attribute in attributes where attribute.size.height != max.size.height {
attribute.frame.origin.y += max.frame.maxY - attribute.frame.maxY
}
}
*/
return layoutAttributes
}
}Cell.swift :
import UIKit
class Cell: UICollectionViewCell {
let label = UILabel()
override init(frame: CGRect) {
super.init(frame: frame)
label.numberOfLines = 0
backgroundColor = .orange
contentView.addSubview(label)
label.translatesAutoresizingMaskIntoConstraints = false
label.topAnchor.constraint(equalTo: contentView.layoutMarginsGuide.topAnchor).isActive = true
label.leadingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.leadingAnchor).isActive = true
label.trailingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.trailingAnchor).isActive = true
label.bottomAnchor.constraint(equalTo: contentView.layoutMarginsGuide.bottomAnchor).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
layoutIfNeeded()
label.preferredMaxLayoutWidth = label.bounds.size.width
layoutAttributes.bounds.size.height = contentView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
return layoutAttributes
}
// Alternative implementation
/*
override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
label.preferredMaxLayoutWidth = layoutAttributes.size.width - contentView.layoutMargins.left - contentView.layoutMargins.right
layoutAttributes.bounds.size.height = contentView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
return layoutAttributes
}
*/
}
답변
나는 UICollectionViewDelegateFlowLayout내에서 구현 UICollectionViewController하고 Cell의 크기를 결정하는 방법을 재정의했습니다. 그런 다음 화면 너비를 내 열 요구 사항으로 나누었습니다. 예를 들어, 각 화면 크기에 3 개의 열을 갖고 싶었습니다. 내 코드는 다음과 같습니다.
- (CGSize)collectionView:(UICollectionView *)collectionView
layout:(UICollectionViewLayout *)collectionViewLayout
sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
CGRect screenRect = [[UIScreen mainScreen] bounds];
CGFloat screenWidth = screenRect.size.width;
float cellWidth = screenWidth / 3.0; //Replace the divisor with the column count requirement. Make sure to have it in float.
CGSize size = CGSizeMake(cellWidth, cellWidth);
return size;
}답변
멍청한 대답에 확장 :
func collectionView(collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
let totalSpace = flowLayout.sectionInset.left
+ flowLayout.sectionInset.right
+ (flowLayout.minimumInteritemSpacing * CGFloat(numberOfItemsPerRow - 1))
let size = Int((collectionView.bounds.width - totalSpace) / CGFloat(numberOfItemsPerRow))
return CGSize(width: size, height: size)
}이것은 셀 사이의 간격을 허용합니다. 그것은 가정 Int이라는 멤버 변수 numberOfItemsPerRow와 모든 세포가 광장과 같은 크기 있음을. jhilgert00의 답변에서 언급했듯이 우리는 방향 변경에도 반응해야하지만 이제는 viewWillTransitionToSizeas willRotateToInterfaceOrientationis depreciated.
답변
다음은 2 열 레이아웃을 갖는 Swift 3의 작업 코드입니다.
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
let nbCol = 2
let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
let totalSpace = flowLayout.sectionInset.left
+ flowLayout.sectionInset.right
+ (flowLayout.minimumInteritemSpacing * CGFloat(nbCol - 1))
let size = Int((collectionView.bounds.width - totalSpace) / CGFloat(nbCol))
return CGSize(width: size, height: size)
}“nbCol”을 원하는 열 수로 자유롭게 변경하십시오.
답변
델리게이트를 사용하여 게으르다면.
extension UICollectionView {
func setItemsInRow(items: Int) {
if let layout = self.collectionViewLayout as? UICollectionViewFlowLayout {
let contentInset = self.contentInset
let itemsInRow: CGFloat = CGFloat(items);
let innerSpace = layout.minimumInteritemSpacing * (itemsInRow - 1.0)
let insetSpace = contentInset.left + contentInset.right + layout.sectionInset.left + layout.sectionInset.right
let width = floor((CGRectGetWidth(frame) - insetSpace - innerSpace) / itemsInRow);
layout.itemSize = CGSizeMake(width, width)
}
}
}PS : 회전 후에도 호출되어야합니다.
답변
Swift 3으로 업데이트되었습니다.
흐름 레이아웃 대신 특정 열 번호와 행 번호에 대해 사용자 지정 레이아웃을 사용하는 것을 선호합니다. 때문에:
- 열 번호가 매우 큰 경우 가로로 드래그 할 수 있습니다.
- 열과 행을 사용하기 때문에 논리적으로 더 적합합니다.
일반 셀 및 헤더 셀 : (UILabel을 xib에 IBOutlet으로 추가) :
class CollectionViewCell: UICollectionViewCell {
@IBOutlet weak var label: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
self.backgroundColor = UIColor.black
label.textColor = UIColor.white
}
}
class CollectionViewHeadCell: UICollectionViewCell {
@IBOutlet weak var label: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
self.backgroundColor = UIColor.darkGray
label.textColor = UIColor.white
}
}맞춤 레이아웃 :
let cellHeight: CGFloat = 100
let cellWidth: CGFloat = 100
class CustomCollectionViewLayout: UICollectionViewLayout {
private var numberOfColumns: Int!
private var numberOfRows: Int!
// It is two dimension array of itemAttributes
private var itemAttributes = [[UICollectionViewLayoutAttributes]]()
// It is one dimension of itemAttributes
private var cache = [UICollectionViewLayoutAttributes]()
override func prepare() {
if self.cache.isEmpty {
self.numberOfColumns = self.collectionView?.numberOfItems(inSection: 0)
self.numberOfRows = self.collectionView?.numberOfSections
// Dynamically change cellWidth if total cell width is smaller than whole bounds
/* if (self.collectionView?.bounds.size.width)!/CGFloat(self.numberOfColumns) > cellWidth {
self.cellWidth = (self.collectionView?.bounds.size.width)!/CGFloat(self.numberOfColumns)
}
*/
for row in 0..<self.numberOfRows {
var row_temp = [UICollectionViewLayoutAttributes]()
for column in 0..<self.numberOfColumns {
let indexPath = NSIndexPath(item: column, section: row)
let attributes = UICollectionViewLayoutAttributes(forCellWith: indexPath as IndexPath)
attributes.frame = CGRect(x: cellWidth*CGFloat(column), y: cellHeight*CGFloat(row), width: cellWidth, height: cellHeight)
row_temp.append(attributes)
self.cache.append(attributes)
}
self.itemAttributes.append(row_temp)
}
}
}
override var collectionViewContentSize: CGSize {
return CGSize(width: CGFloat(self.numberOfColumns)*cellWidth, height: CGFloat(self.numberOfRows)*cellHeight)
}
override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
var layoutAttributes = [UICollectionViewLayoutAttributes]()
for attributes in cache {
if attributes.frame.intersects(rect) {
layoutAttributes.append(attributes)
}
}
return layoutAttributes
}
}CollectionView :
let CellIdentifier = "CellIdentifier"
let HeadCellIdentifier = "HeadCellIdentifier"
class CollectionView: UICollectionView, UICollectionViewDelegate, UICollectionViewDataSource {
init() {
let layout = CustomCollectionViewLayout()
super.init(frame: CGRect.zero, collectionViewLayout: layout)
self.register(UINib(nibName: "CollectionViewCell", bundle: nil), forCellWithReuseIdentifier: CellIdentifier)
self.register(UINib(nibName: "CollectionViewHeadCell", bundle: nil), forCellWithReuseIdentifier: HeadCellIdentifier)
self.isDirectionalLockEnabled = true
self.dataSource = self
self.delegate = self
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func updateCollectionView() {
DispatchQueue.main.async {
self.reloadData()
}
}
// MARK: CollectionView datasource
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 20
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 20
}
override func numberOfItems(inSection section: Int) -> Int {
return 20
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let column = (indexPath as NSIndexPath).row
let row = (indexPath as NSIndexPath).section
if column == 0 {
let cell : CollectionViewHeadCell = collectionView.dequeueReusableCell(withReuseIdentifier: HeadCellIdentifier, for: indexPath) as! CollectionViewHeadCell
cell.label.text = "\(row)"
return cell
}
else if row == 0 {
let cell : CollectionViewHeadCell = collectionView.dequeueReusableCell(withReuseIdentifier: HeadCellIdentifier, for: indexPath) as! CollectionViewHeadCell
cell.label.text = "\(column)"
return cell
}
else {
let cell : CollectionViewCell = collectionView.dequeueReusableCell(withReuseIdentifier: CellIdentifier, for: indexPath) as! CollectionViewCell
cell.label.text = String(format: "%d", arguments: [indexPath.section*indexPath.row])
return cell
}
}
// MARK: CollectionView delegate
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let column = (indexPath as NSIndexPath).row
let row = (indexPath as NSIndexPath).section
print("\(column) \(row)")
}
}ViewController에서 CollectionView 사용 :
class ViewController: UIViewController {
let collectionView = CollectionView()
override func viewDidLoad() {
collectionView.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(collectionView)
self.view.backgroundColor = UIColor.red
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[collectionView]|", options: [], metrics: nil, views: ["collectionView": collectionView]))
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|[collectionView]|", options: [], metrics: nil, views: ["collectionView": collectionView]))
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
collectionView.updateCollectionView()
}
}마지막으로 멋진 CollectionView를 가질 수 있습니다!
