UICollectionView - 动态单元格高度？

Question

我需要显示一堆具有不同高度的collectionViewCell.视图太复杂,我不想手动计算预期的高度.我想强制执行自动布局来计算单元格高度

dequeueReusableCellWithReuseIdentifier在cellForItemAtIndexPathbreak 之外调用collectionView并导致它崩溃

另一个问题是单元格不在单独的xib中,因此我无法手动实例化临时单元并将其用于高度计算.

对此有何解决方案？

public func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

    var cell = collectionView.dequeueReusableCellWithReuseIdentifier(cellIdentifier, forIndexPath: indexPath) as UICollectionViewCell
    configureCell(cell, item: items[indexPath.row])

    cell.contentView.setNeedsLayout()
    cell.contentView.layoutIfNeeded()

    return cell.contentView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize)
}

编辑:

一旦调用dequeueReusableCellWithReuseIdentifier,就会发生崩溃.如果我不调用该方法而是返回一个大小,一切都很好,单元格显示没有计算的大小

流布局中不支持负值或零大小

2015-01-26 18:24:34.231 [13383:9752256] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 1 beyond bounds [0 .. 0]'
*** First throw call stack:
(
    0   CoreFoundation                      0x00000001095aef35 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x0000000109243bb7 objc_exception_throw + 45
    2   CoreFoundation                      0x0000000109499f33 -[__NSArrayM objectAtIndex:] + 227
    3   UIKit                               0x0000000107419d9c -[UICollectionViewFlowLayout _getSizingInfos] + 842
    4   UIKit                               0x000000010741aca9 -[UICollectionViewFlowLayout _fetchItemsInfoForRect:] + 526
    5   UIKit                               0x000000010741651f -[UICollectionViewFlowLayout prepareLayout] + 257
    6   UIKit                               0x000000010742da10 -[UICollectionViewData _prepareToLoadData] + 67
    7   UIKit                               0x00000001074301c6 -[UICollectionViewData layoutAttributesForItemAtIndexPath:] + 44
    8   UIKit                               0x00000001073fddb1 -[UICollectionView _dequeueReusableViewOfKind:withIdentifier:forIndexPath:viewCategory:] + 248
    9                                       0x00000001042b824c _TFC1228BasePaginatingViewController14collectionViewfS0_FTCSo16UICollectionView6layoutCSo22UICollectionViewLayout22sizeForItemAtIndexPathCSo11NSIndexPath_VSC6CGSize + 700
    10                                     0x00000001042b83d4 _TToFC1228BasePaginatingViewController14collectionViewfS0_FTCSo16UICollectionView6layoutCSo22UICollectionViewLayout22sizeForItemAtIndexPathCSo11NSIndexPath_VSC6CGSize + 100
    11  UIKit                               0x0000000107419e2e -[UICollectionViewFlowLayout _getSizingInfos] + 988
    12  UIKit                               0x000000010741aca9 -[UICollectionViewFlowLayout _fetchItemsInfoForRect:] + 526
    13  UIKit                               0x000000010741651f -[UICollectionViewFlowLayout prepareLayout] + 257
    14  UIKit                               0x000000010742da10 -[UICollectionViewData _prepareToLoadData] + 67
    15  UIKit                               0x000000010742e0e9 -[UICollectionViewData validateLayoutInRect:] + 54
    16  UIKit                               0x00000001073f67b8 -[UICollectionView layoutSubviews] + 170
    17  UIKit                               0x0000000106e3c973 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 521
    18  QuartzCore                          0x0000000106b0fde8 -[CALayer layoutSublayers] + 150
    19  QuartzCore                          0x0000000106b04a0e _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
    20  QuartzCore                          0x0000000106b0487e _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
    21  QuartzCore                          0x0000000106a7263e _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 242
    22  QuartzCore                          0x0000000106a7374a _ZN2CA11Transaction6commitEv + 390
    23  QuartzCore                          0x0000000106a73db5 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 89
    24  CoreFoundation                      0x00000001094e3dc7 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
    25  CoreFoundation                      0x00000001094e3d20 __CFRunLoopDoObservers + 368
    26  CoreFoundation                      0x00000001094d9b53 __CFRunLoopRun + 1123
    27  CoreFoundation                      0x00000001094d9486 CFRunLoopRunSpecific + 470
    28  GraphicsServices                    0x000000010be869f0 GSEventRunModal + 161
    29  UIKit                               0x0000000106dc3420 UIApplicationMain + 1282
    30                                      0x000000010435c709 main + 169
    31  libdyld.dylib                       0x000000010a0f2145 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Answer 1

我刚刚在UICollectionView上遇到了这个问题,我解决它的方式类似于上面的答案,但是以纯UICollectionView方式.

1. 创建一个自定义UICollectionViewCell,其中包含您将填充它的任何内容,以使其动态化.我为它创建了自己的.xib,因为它似乎是最简单的方法.

2. 在.xib中添加约束,允许从上到下计算单元格.如果你没有考虑到所有的高度,重新调整大小将不起作用.假设您有一个顶部的视图,然后是一个标签,下面是另一个标签.您需要将约束连接到单元格的顶部到该视图的顶部,然后将视图的底部连接到第一个标签的顶部,将第一个标签的底部连接到第二个标签的顶部,以及第二个标签的底部到底部的细胞.

3. 将.xib加载到viewcontroller中并使用collectionView on注册它 viewDidLoad

   let nib = UINib(nibName: CustomCellName, bundle: nil)
   self.collectionView!.registerNib(nib, forCellWithReuseIdentifier: "customCellID")`
   

4. 将该xib的第二个副本加载到类中并将其存储为属性,以便您可以使用它来确定该单元格的大小

   let sizingNibNew = NSBundle.mainBundle().loadNibNamed(CustomCellName, owner: CustomCellName.self, options: nil) as NSArray
   self.sizingNibNew = (sizingNibNew.objectAtIndex(0) as? CustomViewCell)!
   

5. 落实UICollectionViewFlowLayoutDelegate在您的视图控制器.重要的方法叫做sizeForItemAtIndexPath.在该方法中,您需要从indexPath中提取与该单元格关联的数据源中的数据.然后配置sizingCell并调用preferredLayoutSizeFittingSize.该方法返回一个CGSize,它由宽度减去内容插入和返回的高度组成self.sizingCell.preferredLayoutSizeFittingSize(targetSize).

   override func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
       guard let data = datasourceArray?[indexPath.item] else {
           return CGSizeZero
       }
       let sectionInset = self.collectionView?.collectionViewLayout.sectionInset
       let widthToSubtract = sectionInset!.left + sectionInset!.right
   
       let requiredWidth = collectionView.bounds.size.width
   
   
       let targetSize = CGSize(width: requiredWidth, height: 0)
   
       sizingNibNew.configureCell(data as! CustomCellData, delegate: self)
       let adequateSize = self.sizingNibNew.preferredLayoutSizeFittingSize(targetSize)
       return CGSize(width: (self.collectionView?.bounds.width)! - widthToSubtract, height: adequateSize.height)
    }
   

6. 在自定义单元格本身的类中,您需要覆盖awakeFromNib并告诉contentView它的大小需要灵活

    override func awakeFromNib() {
       super.awakeFromNib()
       self.contentView.autoresizingMask = [UIViewAutoresizing.FlexibleHeight]
    }
   

7. 在自定义单元格覆盖中 layoutSubviews

    override func layoutSubviews() {
      self.layoutIfNeeded()
     }
   

8. 在自定义单元工具的类中preferredLayoutSizeFittingSize.这是您需要对正在布置的项目进行任何欺骗的地方.如果是标签,您需要告诉它首选的MaxWidth应该是什么.

   func preferredLayoutSizeFittingSize(_ targetSize: CGSize)-> CGSize {
   
       let originalFrame = self.frame
       let originalPreferredMaxLayoutWidth = self.label.preferredMaxLayoutWidth
   
   
       var frame = self.frame
       frame.size = targetSize
       self.frame = frame
   
       self.setNeedsLayout()
       self.layoutIfNeeded()
       self.label.preferredMaxLayoutWidth = self.questionLabel.bounds.size.width
   
   
       // calling this tells the cell to figure out a size for it based on the current items set
       let computedSize = self.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize)
   
       let newSize = CGSize(width:targetSize.width, height:computedSize.height)
   
       self.frame = originalFrame
       self.questionLabel.preferredMaxLayoutWidth = originalPreferredMaxLayoutWidth
   
       return newSize
   }
   

所有这些步骤都应该给你正确的尺寸.如果你得到0或其他时髦的数字而不是你没有正确设置你的约束.

Answer 2

这是一个Ray Wenderlich教程,向您展示如何使用AutoLayout动态调整大小UITableViewCell.我认为它会是一样的UICollectionViewCell.

但是,基本上,您最终会出列并配置原型单元并获取其高度.阅读本文后,我决定不实现这个方法,只是写一些清晰,明确的大小调整代码.

这就是我认为整篇文章的"秘诀":

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return [self heightForBasicCellAtIndexPath:indexPath];
}

- (CGFloat)heightForBasicCellAtIndexPath:(NSIndexPath *)indexPath {
    static RWBasicCell *sizingCell = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sizingCell = [self.tableView dequeueReusableCellWithIdentifier:RWBasicCellIdentifier];
    });

    [self configureBasicCell:sizingCell atIndexPath:indexPath];
    return [self calculateHeightForConfiguredSizingCell:sizingCell];
}

- (CGFloat)calculateHeightForConfiguredSizingCell:(UITableViewCell *)sizingCell {
    [sizingCell setNeedsLayout];
    [sizingCell layoutIfNeeded];

    CGSize size = [sizingCell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize];
    return size.height + 1.0f; // Add 1.0f for the cell separator height
}

编辑:我对你的崩溃做了一些研究,并决定没有自定义XIB就没有办法完成这项工作.虽然这有点令人沮丧,但您应该能够从故事板剪切并粘贴到自定义的空XIB中.

完成后,像下面这样的代码将帮助您:

//  ViewController.m
#import "ViewController.h"
#import "CollectionViewCell.h"
@interface ViewController () <UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout> {

}
@property (weak, nonatomic) IBOutlet CollectionViewCell *cell;
@property (weak, nonatomic) IBOutlet UICollectionView   *collectionView;
@end
@implementation ViewController
- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor lightGrayColor];
    [self.collectionView registerNib:[UINib nibWithNibName:@"CollectionViewCell" bundle:nil] forCellWithReuseIdentifier:@"cell"];
}
- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    NSLog(@"viewDidAppear...");
}
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 1;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return 50;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
    return 10.0f;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
    return 10.0f;
}
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    return [self sizingForRowAtIndexPath:indexPath];
}
- (CGSize)sizingForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *title                  = @"This is a long title that will cause some wrapping to occur. This is a long title that will cause some wrapping to occur.";
    static NSString *subtitle               = @"This is a long subtitle that will cause some wrapping to occur. This is a long subtitle that will cause some wrapping to occur.";
    static NSString *buttonTitle            = @"This is a really long button title that will cause some wrapping to occur.";
    static CollectionViewCell *sizingCell   = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sizingCell                          = [[NSBundle mainBundle] loadNibNamed:@"CollectionViewCell" owner:self options:nil][0];
    });
    [sizingCell configureWithTitle:title subtitle:[NSString stringWithFormat:@"%@: Number %d.", subtitle, (int)indexPath.row] buttonTitle:buttonTitle];
    [sizingCell setNeedsLayout];
    [sizingCell layoutIfNeeded];
    CGSize cellSize = [sizingCell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize];
    NSLog(@"cellSize: %@", NSStringFromCGSize(cellSize));
    return cellSize;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *title                  = @"This is a long title that will cause some wrapping to occur. This is a long title that will cause some wrapping to occur.";
    static NSString *subtitle               = @"This is a long subtitle that will cause some wrapping to occur. This is a long subtitle that will cause some wrapping to occur.";
    static NSString *buttonTitle            = @"This is a really long button title that will cause some wrapping to occur.";
    CollectionViewCell *cell                = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];
    [cell configureWithTitle:title subtitle:[NSString stringWithFormat:@"%@: Number %d.", subtitle, (int)indexPath.row] buttonTitle:buttonTitle];
    return cell;
}
@end

上面的代码(以及一个非常基本的UICollectionViewCell子类和相关的XIB)给了我这个:

Answer 3

我们可以在没有xib的情况下维护集合视图单元格的动态高度(仅使用故事板).

- (CGSize)collectionView:(UICollectionView *)collectionView
                  layout:(UICollectionViewLayout*)collectionViewLayout
  sizeForItemAtIndexPath:(NSIndexPath *)indexPath {

        NSAttributedString* labelString = [[NSAttributedString alloc] initWithString:@"Your long string goes here" attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:17.0]}];
        CGRect cellRect = [labelString boundingRectWithSize:CGSizeMake(cellWidth, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin context:nil];

        return CGSizeMake(cellWidth, cellRect.size.height);
}

确保IB中的numberOfLines应为0.

Answer 4

TL; DR:扫描到图像,然后在这里查看工作项目.

更新我的答案,找到我找到的更简单的解决方案..

在我的情况下,我想修复宽度,并有可变高度单元格.我想要一个可以重复使用的解决方案来处理轮换并且不需要很多干预.

我得到的是覆盖(只是)systemLayoutFitting(...)在集合单元格中(在这种情况下是我的基类),并首先contentView通过为已知维度添加约束来阻止UICollectionView设置错误维度的努力,在这种情况下,宽度.

class EstimatedWidthCell: UICollectionViewCell {
    override init(frame: CGRect) {
        super.init(frame: frame)
        contentView.translatesAutoresizingMaskIntoConstraints = false
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        contentView.translatesAutoresizingMaskIntoConstraints = false
    }

    override func systemLayoutSizeFitting(
        _ targetSize: CGSize, withHorizontalFittingPriority
        horizontalFittingPriority: UILayoutPriority,
        verticalFittingPriority: UILayoutPriority) -> CGSize {

        width.constant = targetSize.width

然后返回单元格的最终大小 - 用于(这感觉就像一个bug)单元格本身的维度,但不是contentView- 否则会被限制为冲突的大小(因此上面的约束).为了计算正确的单元格大小,我对要浮动的维度使用较低的优先级,然后返回所需的高度以使内容适合我想要修复的宽度:

        let size = contentView.systemLayoutSizeFitting(
            CGSize(width: targetSize.width, height: 1),
            withHorizontalFittingPriority: .required,
            verticalFittingPriority: verticalFittingPriority)

        print("\(#function) \(#line) \(targetSize) -> \(size)")
        return size
    }

    lazy var width: NSLayoutConstraint = {
        return contentView.widthAnchor
            .constraint(equalToConstant: bounds.size.width)
            .isActive(true)
    }()
}

但是这个宽度来自哪里？它是通过estimatedItemSize集合视图的流布局配置的:

lazy var collectionView: UICollectionView = {
    let view = UICollectionView(frame: CGRect(), collectionViewLayout: layout)
    view.backgroundColor = .cyan
    view.translatesAutoresizingMaskIntoConstraints = false
    return view
}()

lazy var layout: UICollectionViewFlowLayout = {
    let layout = UICollectionViewFlowLayout()
    let width = view.bounds.size.width // should adjust for inset
    layout.estimatedItemSize = CGSize(width: width, height: 10)
    layout.scrollDirection = .vertical
    return layout
}()

最后,为了处理旋转,我实现trailCollectionDidChange了使布局无效:

override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
    layout.estimatedItemSize = CGSize(width: view.bounds.size.width, height: 10)
    layout.invalidateLayout()
    super.traitCollectionDidChange(previousTraitCollection)
}

最终结果如下:

我在这里发表了一份工作样本.

Answer 5

斯威夫特4. *

我为UICollectionViewCell创建了一个Xib，这似乎是个好方法。

extension ViewController: UICollectionViewDelegateFlowLayout {

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return size(indexPath: indexPath)
    }

    private func size(for indexPath: IndexPath) -> CGSize {
        // load cell from Xib
        let cell = Bundle.main.loadNibNamed("ACollectionViewCell", owner: self, options: nil)?.first as! ACollectionViewCell

        // configure cell with data in it
        let data = self.data[indexPath.item]
        cell.configure(withData: data)

        cell.setNeedsLayout()
        cell.layoutIfNeeded()

        // width that you want
        let width = collectionView.frame.width
        let height: CGFloat = 0

        let targetSize = CGSize(width: width, height: height)

        // get size with width that you want and automatic height
        let size = cell.contentView.systemLayoutSizeFitting(targetSize, withHorizontalFittingPriority: .defaultHigh, verticalFittingPriority: .fittingSizeLevel)
        // if you want height and width both to be dynamic use below
        // let size = cell.contentView.systemLayoutSizeFitting(UILayoutFittingCompressedSize)

        return size
    }
}

#note：在这种大小确定的情况下配置数据时，我不建议设置图像。它给了我失真/不需要的结果。配置文本只会给我以下结果。

Answer 6

似乎这是一个很受欢迎的问题，所以我将尽我的微薄贡献。

下面的代码是Swift 4解决方案，用于无故事板设置。它利用了先前答案中的一些方法，因此可以防止因设备旋转而引起的“自动布局”警告。

如果代码示例有点长，我很抱歉。我想提供一个由StackOverflow完全托管的“易于使用”的解决方案。如果您对帖子有任何建议-请分享想法，我将相应地更新。

设置：

两类：ViewController.swift和MultilineLabelCell.swift-包含single的单元格UILabel。

MultilineLabelCell.swift

import UIKit

class MultilineLabelCell: UICollectionViewCell {
    static let reuseId = "MultilineLabelCellReuseId"

    private let label: UILabel = UILabel(frame: .zero)

    override init(frame: CGRect) {
        super.init(frame: frame)

        layer.borderColor = UIColor.red.cgColor
        layer.borderWidth = 1.0

        label.numberOfLines = 0
        label.lineBreakMode = .byWordWrapping

        let labelInset = UIEdgeInsets(top: 10, left: 10, bottom: -10, right: -10)
        contentView.addSubview(label)
        label.translatesAutoresizingMaskIntoConstraints = false
        label.topAnchor.constraint(equalTo: contentView.layoutMarginsGuide.topAnchor, constant: labelInset.top).isActive = true
        label.leadingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.leadingAnchor, constant: labelInset.left).isActive = true
        label.trailingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.trailingAnchor, constant: labelInset.right).isActive = true
        label.bottomAnchor.constraint(equalTo: contentView.layoutMarginsGuide.bottomAnchor, constant: labelInset.bottom).isActive = true

        label.layer.borderColor = UIColor.black.cgColor
        label.layer.borderWidth = 1.0
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("Storyboards are quicker, easier, more seductive. Not stronger then Code.")
    }

    func configure(text: String?) {
        label.text = text
    }

    override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
        label.preferredMaxLayoutWidth = layoutAttributes.size.width - contentView.layoutMargins.left - contentView.layoutMargins.left
        layoutAttributes.bounds.size.height = systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
        return layoutAttributes
    }
}

ViewController.swift

import UIKit

let samuelQuotes = [
    "Samuel says", 
    "Add different length strings here for better testing"
]

class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
    private(set) var collectionView: UICollectionView

    // Initializers
    init() {
        // Create new `UICollectionView` and set `UICollectionViewFlowLayout` as its layout
        collectionView = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder aDecoder: NSCoder) {
        // Create new `UICollectionView` and set `UICollectionViewFlowLayout` as its layout
        collectionView = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())
        super.init(coder: aDecoder)
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        title = "Dynamic size sample"

        // Register Cells
        collectionView.register(MultilineLabelCell.self, forCellWithReuseIdentifier: MultilineLabelCell.reuseId)

        // Add `coolectionView` to display hierarchy and setup its appearance
        view.addSubview(collectionView)
        collectionView.backgroundColor = .white
        collectionView.contentInsetAdjustmentBehavior = .always
        collectionView.contentInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)

        // Setup Autolayout constraints
        collectionView.translatesAutoresizingMaskIntoConstraints = false
        collectionView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0).isActive = true
        collectionView.leftAnchor.constraint(equalTo: view.leftAnchor, constant: 0).isActive = true
        collectionView.topAnchor.constraint(equalTo: view.topAnchor, constant: 0).isActive = true
        collectionView.rightAnchor.constraint(equalTo: view.rightAnchor, constant: 0).isActive = true

        // Setup `dataSource` and `delegate`
        collectionView.dataSource = self
        collectionView.delegate = self

        (collectionView.collectionViewLayout as! UICollectionViewFlowLayout).estimatedItemSize = UICollectionViewFlowLayout.automaticSize
        (collectionView.collectionViewLayout as! UICollectionViewFlowLayout).sectionInsetReference = .fromLayoutMargins
    }

    // MARK: - UICollectionViewDataSource -
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: MultilineLabelCell.reuseId, for: indexPath) as! MultilineLabelCell
        cell.configure(text: samuelQuotes[indexPath.row])
        return cell
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return samuelQuotes.count
    }

    // MARK: - UICollectionViewDelegateFlowLayout -
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let sectionInset = (collectionViewLayout as! UICollectionViewFlowLayout).sectionInset
        let referenceHeight: CGFloat = 100 // Approximate height of your cell
        let referenceWidth = collectionView.safeAreaLayoutGuide.layoutFrame.width
            - sectionInset.left
            - sectionInset.right
            - collectionView.contentInset.left
            - collectionView.contentInset.right
        return CGSize(width: referenceWidth, height: referenceHeight)
    }
}

要运行此示例，请创建新的Xcode项目，创建相应的文件，并将AppDelegate内容替换为以下代码：

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?
    var navigationController: UINavigationController?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        window = UIWindow(frame: UIScreen.main.bounds)

        if let window = window {
            let vc = ViewController()
            navigationController = UINavigationController(rootViewController: vc)
            window.rootViewController = navigationController
            window.makeKeyAndVisible()
        }

        return true
    }
}