1. iOS 13+ के लिए समाधान
स्विफ्ट 5.1 और आईओएस 13 के साथ, आप अपनी समस्या को हल करने के लिए कंपोजल लेआउट ऑब्जेक्ट का उपयोग कर सकते हैं ।
निम्न पूर्ण नमूना कोड दिखाता है कि UILabel
पूर्ण-चौड़ाई के अंदर मल्टीलाइन कैसे प्रदर्शित करें UICollectionViewCell
:
CollectionViewController.swift
import UIKit
class CollectionViewController: UICollectionViewController {
let items = [
[
"Lorem ipsum dolor sit amet.",
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris. Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
],
[
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt.",
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
],
[
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt.",
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
"Lorem ipsum. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.",
]
]
override func viewDidLoad() {
super.viewDidLoad()
let size = NSCollectionLayoutSize(
widthDimension: NSCollectionLayoutDimension.fractionalWidth(1),
heightDimension: NSCollectionLayoutDimension.estimated(44)
)
let item = NSCollectionLayoutItem(layoutSize: size)
let group = NSCollectionLayoutGroup.horizontal(layoutSize: size, subitem: item, count: 1)
let section = NSCollectionLayoutSection(group: group)
section.contentInsets = NSDirectionalEdgeInsets(top: 10, leading: 10, bottom: 10, trailing: 10)
section.interGroupSpacing = 10
let headerFooterSize = NSCollectionLayoutSize(
widthDimension: .fractionalWidth(1.0),
heightDimension: .absolute(40)
)
let sectionHeader = NSCollectionLayoutBoundarySupplementaryItem(
layoutSize: headerFooterSize,
elementKind: "SectionHeaderElementKind",
alignment: .top
)
section.boundarySupplementaryItems = [sectionHeader]
let layout = UICollectionViewCompositionalLayout(section: section)
collectionView.collectionViewLayout = layout
collectionView.register(CustomCell.self, forCellWithReuseIdentifier: "CustomCell")
collectionView.register(HeaderView.self, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "HeaderView")
}
override func numberOfSections(in collectionView: UICollectionView) -> Int {
return items.count
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return items[section].count
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CustomCell", for: indexPath) as! CustomCell
cell.label.text = items[indexPath.section][indexPath.row]
return cell
}
override func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "HeaderView", for: indexPath) as! HeaderView
headerView.label.text = "Header"
return headerView
}
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransition(to: size, with: coordinator)
coordinator.animate(alongsideTransition: { context in
self.collectionView.collectionViewLayout.invalidateLayout()
}, completion: nil)
}
}
HeaderView.swift
import UIKit
class HeaderView: UICollectionReusableView {
let label = UILabel()
override init(frame: CGRect) {
super.init(frame: frame)
backgroundColor = .magenta
addSubview(label)
label.translatesAutoresizingMaskIntoConstraints = false
label.centerXAnchor.constraint(equalTo: centerXAnchor).isActive = true
label.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
CustomCell.swift
import UIKit
class CustomCell: 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.topAnchor).isActive = true
label.leadingAnchor.constraint(equalTo: contentView.leadingAnchor).isActive = true
label.trailingAnchor.constraint(equalTo: contentView.trailingAnchor).isActive = true
label.bottomAnchor.constraint(equalTo: contentView.bottomAnchor).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
अपेक्षित प्रदर्शन:
2. iOS 11+ के लिए समाधान
स्विफ्ट 5.1 और आईओएस 11 के साथ, आप UICollectionViewFlowLayout
इसकी estimatedItemSize
संपत्ति को उप-वर्ग और सेट कर सकते हैं UICollectionViewFlowLayout.automaticSize
(यह उस सिस्टम को बताता है जिसे आप ऑटोरेस्पोन्डिंग UICollectionViewCell
एस से निपटना चाहते हैं )। इसके बाद आप ओवरराइड करने के लिए होगा layoutAttributesForElements(in:)
और layoutAttributesForItem(at:)
क्रम में करने के लिए सेट कोशिकाओं चौड़ाई। अंत में, आपको अपनी सेल की preferredLayoutAttributesFitting(_:)
विधि को ओवरराइड करना होगा और इसकी ऊंचाई की गणना करनी होगी ।
निम्न पूर्ण कोड दिखाता है कि UILabel
पूर्ण-चौड़ाई के अंदर बहुस्तरीय को कैसे प्रदर्शित किया जाए UIcollectionViewCell
( UICollectionView
सुरक्षित क्षेत्र और UICollectionViewFlowLayout
इनसेट द्वारा विवश ):
CollectionViewController.swift
import UIKit
class CollectionViewController: UICollectionViewController {
let items = [
[
"Lorem ipsum dolor sit amet.",
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris. Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
],
[
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt.",
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
],
[
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt.",
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
"Lorem ipsum. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.",
]
]
let customFlowLayout = CustomFlowLayout()
override func viewDidLoad() {
super.viewDidLoad()
customFlowLayout.sectionInsetReference = .fromContentInset // .fromContentInset is default
customFlowLayout.estimatedItemSize = UICollectionViewFlowLayout.automaticSize
customFlowLayout.minimumInteritemSpacing = 10
customFlowLayout.minimumLineSpacing = 10
customFlowLayout.sectionInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
customFlowLayout.headerReferenceSize = CGSize(width: 0, height: 40)
collectionView.collectionViewLayout = customFlowLayout
collectionView.contentInsetAdjustmentBehavior = .always
collectionView.register(CustomCell.self, forCellWithReuseIdentifier: "CustomCell")
collectionView.register(HeaderView.self, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "HeaderView")
}
override func numberOfSections(in collectionView: UICollectionView) -> Int {
return items.count
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return items[section].count
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CustomCell", for: indexPath) as! CustomCell
cell.label.text = items[indexPath.section][indexPath.row]
return cell
}
override func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "HeaderView", for: indexPath) as! HeaderView
headerView.label.text = "Header"
return headerView
}
}
CustomFlowLayout.swift
import UIKit
final class CustomFlowLayout: UICollectionViewFlowLayout {
override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
let layoutAttributesObjects = super.layoutAttributesForElements(in: rect)?.map{ $0.copy() } as? [UICollectionViewLayoutAttributes]
layoutAttributesObjects?.forEach({ layoutAttributes in
if layoutAttributes.representedElementCategory == .cell {
if let newFrame = layoutAttributesForItem(at: layoutAttributes.indexPath)?.frame {
layoutAttributes.frame = newFrame
}
}
})
return layoutAttributesObjects
}
override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
guard let collectionView = collectionView else {
fatalError()
}
guard let layoutAttributes = super.layoutAttributesForItem(at: indexPath)?.copy() as? UICollectionViewLayoutAttributes else {
return nil
}
layoutAttributes.frame.origin.x = sectionInset.left
layoutAttributes.frame.size.width = collectionView.safeAreaLayoutGuide.layoutFrame.width - sectionInset.left - sectionInset.right
return layoutAttributes
}
}
HeaderView.swift
import UIKit
class HeaderView: UICollectionReusableView {
let label = UILabel()
override init(frame: CGRect) {
super.init(frame: frame)
backgroundColor = .magenta
addSubview(label)
label.translatesAutoresizingMaskIntoConstraints = false
label.centerXAnchor.constraint(equalTo: centerXAnchor).isActive = true
label.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
CustomCell.swift
import UIKit
class CustomCell: 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.topAnchor).isActive = true
label.leadingAnchor.constraint(equalTo: contentView.leadingAnchor).isActive = true
label.trailingAnchor.constraint(equalTo: contentView.trailingAnchor).isActive = true
label.bottomAnchor.constraint(equalTo: contentView.bottomAnchor).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
let layoutAttributes = super.preferredLayoutAttributesFitting(layoutAttributes)
layoutIfNeeded()
layoutAttributes.frame.size = systemLayoutSizeFitting(UIView.layoutFittingCompressedSize, withHorizontalFittingPriority: .required, verticalFittingPriority: .fittingSizeLevel)
return layoutAttributes
}
}
यहाँ कुछ वैकल्पिक कार्यान्वयन हैं preferredLayoutAttributesFitting(_:)
:
override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
let targetSize = CGSize(width: layoutAttributes.frame.width, height: 0)
layoutAttributes.frame.size = contentView.systemLayoutSizeFitting(targetSize, withHorizontalFittingPriority: .required, verticalFittingPriority: .fittingSizeLevel)
return layoutAttributes
}
override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
label.preferredMaxLayoutWidth = layoutAttributes.frame.width
layoutAttributes.frame.size.height = contentView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
return layoutAttributes
}
अपेक्षित प्रदर्शन: