swift - how - Cómo crear UICollectionViewCell programáticamente

uicollectionview swift 4

Question

Estoy tratando de crear UICollectionView programáticamente. Necesito agregar etiquetas dentro de las celdas, así que CollectionViewCell clase CollectionViewCell .

Esta es la clase:

import UIKit
class MyCollectionViewCell: UICollectionViewCell {
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}

Y esta es la clase de implementación collectionView:

import UIKit
class TwoViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout, UICollectionViewDelegate {
let leftAndRightPaddings: CGFloat = 80.0
let numberOfItemsPerRow: CGFloat = 7.0
let screenSize: CGRect = UIScreen.mainScreen().bounds
private let cellReuseIdentifier = "collectionCell"
var items = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31"]
override func viewDidLoad() {
super.viewDidLoad()
let flowLayout = UICollectionViewFlowLayout()
let collectionView = UICollectionView(frame: self.view.bounds, collectionViewLayout: flowLayout)
collectionView.registerClass(MyCollectionViewCell.self, forCellWithReuseIdentifier: cellReuseIdentifier)
collectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "collectionCell")
collectionView.delegate = self
collectionView.dataSource = self
collectionView.backgroundColor = UIColor.cyanColor()
self.view.addSubview(collectionView)
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
return self.items.count
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell
{
let cell = collectionView.dequeueReusableCellWithReuseIdentifier(cellReuseIdentifier, forIndexPath: indexPath) as! MyCollectionViewCell
cell.backgroundColor = UIColor.greenColor()
return cell
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize
{
let width = (screenSize.width-leftAndRightPaddings)/numberOfItemsPerRow
return CGSizeMake(width, width)
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets
{
return UIEdgeInsets(top: 20, left: 8, bottom: 5, right: 8)
}
}

El error ocurre cuando la célula produce:

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell
{
let cell = collectionView.dequeueReusableCellWithReuseIdentifier(cellReuseIdentifier, forIndexPath: indexPath) as! MyCollectionViewCell

El error es:

Could not cast value of type ''UICollectionViewCell'' (0x1033cc820) to ''CollectionViewProgramatically.MyCollectionViewCell'' (0x1015a4f88).

Answer 1

Cambié la respuesta de Bob Lee por Swift 4

import UIKit
class noNibCollectionViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
var collectionview: UICollectionView!
var cellId = "Cell"
override func viewDidLoad() {
super.viewDidLoad()
// Create an instance of UICollectionViewFlowLayout since you cant
// Initialize UICollectionView without a layout
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
layout.itemSize = CGSize(width: view.frame.width, height: 700)
collectionview = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
collectionview.dataSource = self
collectionview.delegate = self
collectionview.register(FreelancerCell.self, forCellWithReuseIdentifier: cellId)
collectionview.showsVerticalScrollIndicator = false
collectionview.backgroundColor = UIColor.white
self.view.addSubview(collectionview)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 10
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionview.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! FreelancerCell
return cell
}
}
class FreelancerCell: UICollectionViewCell {
let profileImageButton: UIButton = {
let button = UIButton()
button.backgroundColor = UIColor.white
button.layer.cornerRadius = 18
button.clipsToBounds = true
button.setImage(UIImage(named: "Profile"), for: .normal)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
let nameLabel: UILabel = {
let label = UILabel()
label.font = UIFont.systemFont(ofSize: 14)
label.textColor = UIColor.darkGray
label.text = "Bob Lee"
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let distanceLabel: UILabel = {
let label = UILabel()
label.textColor = UIColor.lightGray
label.font = UIFont.systemFont(ofSize: 14)
label.text = "30000 miles"
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let pricePerHourLabel: UILabel = {
let label = UILabel()
label.textColor = UIColor.darkGray
label.font = UIFont.systemFont(ofSize: 14)
label.text = "$40/hour"
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let ratingLabel: UILabel = {
let label = UILabel()
label.textColor = UIColor.lightGray
label.font = UIFont.systemFont(ofSize: 14)
label.text = "4.9+"
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let showCaseImageView: UIImageView = {
let imageView = UIImageView()
imageView.backgroundColor = UIColor.white
imageView.image = UIImage(named: "Profile")
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
let likesLabel: UILabel = {
let label = UILabel()
label.textColor = UIColor.lightGray
label.font = UIFont.systemFont(ofSize: 14)
label.text = "424 likes"
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let topSeparatorView: UIView = {
let view = UIView()
view.backgroundColor = UIColor.darkGray
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
let bottomSeparatorView: UIView = {
let view = UIView()
view.backgroundColor = UIColor.darkGray
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
let likeButton: UIButton = {
let button = UIButton()
button.setTitle("Like", for: .normal)
button.titleLabel?.font = UIFont.systemFont(ofSize: 18)
button.setTitleColor(UIColor.darkGray, for: .normal)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
let hireButton: UIButton = {
let button = UIButton()
button.setTitle("Hire", for: .normal)
button.titleLabel?.font = UIFont.systemFont(ofSize: 18)
button.setTitleColor(UIColor.darkGray, for: .normal)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
let messageButton: UIButton = {
let button = UIButton()
button.setTitle("Message", for: .normal)
button.titleLabel?.font = UIFont.systemFont(ofSize: 18)
button.setTitleColor(UIColor.darkGray, for: .normal)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
let stackView: UIStackView = {
let sv = UIStackView()
sv.axis = UILayoutConstraintAxis.horizontal
sv.alignment = UIStackViewAlignment.center
sv.distribution = UIStackViewDistribution.fillEqually
sv.translatesAutoresizingMaskIntoConstraints = false;
return sv
}()
override init(frame: CGRect) {
super.init(frame: frame)
addViews()
}
func addViews(){
backgroundColor = UIColor.black
addSubview(profileImageButton)
addSubview(nameLabel)
addSubview(distanceLabel)
addSubview(pricePerHourLabel)
addSubview(ratingLabel)
addSubview(showCaseImageView)
addSubview(likesLabel)
addSubview(topSeparatorView)
addSubview(bottomSeparatorView)
// Stack View
addSubview(likeButton)
addSubview(messageButton)
addSubview(hireButton)
addSubview(stackView)
profileImageButton.leftAnchor.constraint(equalTo: leftAnchor, constant: 5).isActive = true
profileImageButton.topAnchor.constraint(equalTo: topAnchor, constant: 10).isActive = true
profileImageButton.heightAnchor.constraint(equalToConstant: 36).isActive = true
profileImageButton.widthAnchor.constraint(equalToConstant: 36).isActive = true
nameLabel.leftAnchor.constraint(equalTo: profileImageButton.rightAnchor, constant: 5).isActive = true
nameLabel.centerYAnchor.constraint(equalTo: profileImageButton.centerYAnchor, constant: -8).isActive = true
nameLabel.rightAnchor.constraint(equalTo: pricePerHourLabel.leftAnchor).isActive = true
distanceLabel.leftAnchor.constraint(equalTo: nameLabel.leftAnchor).isActive = true
distanceLabel.centerYAnchor.constraint(equalTo: profileImageButton.centerYAnchor, constant: 8).isActive = true
distanceLabel.widthAnchor.constraint(equalToConstant: 300)
pricePerHourLabel.rightAnchor.constraint(equalTo: rightAnchor, constant: -10).isActive = true
pricePerHourLabel.centerYAnchor.constraint(equalTo: nameLabel.centerYAnchor).isActive = true
// Distance depeneded on the priceLabel and distance Label
ratingLabel.rightAnchor.constraint(equalTo: pricePerHourLabel.rightAnchor).isActive = true
ratingLabel.centerYAnchor.constraint(equalTo: distanceLabel.centerYAnchor).isActive = true
showCaseImageView.topAnchor.constraint(equalTo: profileImageButton.bottomAnchor, constant: 10).isActive = true
showCaseImageView.widthAnchor.constraint(equalTo: widthAnchor).isActive = true
showCaseImageView.heightAnchor.constraint(equalToConstant: UIScreen.main.bounds.width - 20).isActive = true
likesLabel.topAnchor.constraint(equalTo: showCaseImageView.bottomAnchor, constant: 10).isActive = true
likesLabel.leftAnchor.constraint(equalTo: profileImageButton.leftAnchor).isActive = true
topSeparatorView.topAnchor.constraint(equalTo: likesLabel.bottomAnchor, constant: 10).isActive = true
topSeparatorView.widthAnchor.constraint(equalTo: widthAnchor).isActive = true
topSeparatorView.heightAnchor.constraint(equalToConstant: 0.5).isActive = true
stackView.addArrangedSubview(likeButton)
stackView.addArrangedSubview(hireButton)
stackView.addArrangedSubview(messageButton)
stackView.topAnchor.constraint(equalTo: topSeparatorView.bottomAnchor, constant: 4).isActive = true
stackView.widthAnchor.constraint(equalTo: widthAnchor).isActive = true
stackView.centerXAnchor.constraint(equalTo: centerXAnchor).isActive = true
bottomSeparatorView.topAnchor.constraint(equalTo: stackView.bottomAnchor, constant: 4).isActive = true
bottomSeparatorView.widthAnchor.constraint(equalTo: widthAnchor).isActive = true
bottomSeparatorView.heightAnchor.constraint(equalToConstant: 0.5).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}

Answer 2

Intenta copiar y pegar este código en tu xcode, debería funcionar

//
// HomeVIewController.swift
// Photolancer
//
// Created by Lee SangJoon on 9/8/16.
// Copyright © 2016 Givnite. All rights reserved.
//
import UIKit
class HomeViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
var collectionview: UICollectionView!
var cellId = "Cell"
override func viewDidLoad() {
super.viewDidLoad()
// Create an instance of UICollectionViewFlowLayout since you cant
// Initialize UICollectionView without a layout
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
layout.itemSize = CGSize(width: view.frame.width, height: 700)
collectionview = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
collectionview.dataSource = self
collectionview.delegate = self
collectionview.registerClass(FreelancerCell.self, forCellWithReuseIdentifier: cellId)
collectionview.showsVerticalScrollIndicator = false
collectionview.backgroundColor = UIColor.whiteColor()
self.view.addSubview(collectionview)
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 10
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionview.dequeueReusableCellWithReuseIdentifier(cellId, forIndexPath: indexPath) as! FreelancerCell
return cell
}
}
class FreelancerCell: UICollectionViewCell {
let profileImageButton: UIButton = {
let button = UIButton()
button.backgroundColor = UIColor.whiteColor()
button.layer.cornerRadius = 18
button.clipsToBounds = true
button.setImage(UIImage(named: "Profile"), forState: .Normal)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
let nameLabel: UILabel = {
let label = UILabel()
label.font = UIFont.systemFontOfSize(14)
label.textColor = UIColor.darkGrayColor()
label.text = "Bob Lee"
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let distanceLabel: UILabel = {
let label = UILabel()
label.textColor = UIColor.lightGrayColor()
label.font = UIFont.systemFontOfSize(14)
label.text = "30000 miles"
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let pricePerHourLabel: UILabel = {
let label = UILabel()
label.textColor = UIColor.darkGrayColor()
label.font = UIFont.systemFontOfSize(14)
label.text = "$40/hour"
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let ratingLabel: UILabel = {
let label = UILabel()
label.textColor = UIColor.lightGrayColor()
label.font = UIFont.systemFontOfSize(14)
label.text = "4.9+"
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let showCaseImageView: UIImageView = {
let imageView = UIImageView()
imageView.backgroundColor = UIColor.whiteColor()
imageView.image = UIImage(named: "Profile")
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
let likesLabel: UILabel = {
let label = UILabel()
label.textColor = UIColor.lightGrayColor()
label.font = UIFont.systemFontOfSize(14)
label.text = "424 likes"
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
let topSeparatorView: UIView = {
let view = UIView()
view.backgroundColor = UIColor.darkGrayColor()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
let bottomSeparatorView: UIView = {
let view = UIView()
view.backgroundColor = UIColor.darkGrayColor()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
let likeButton: UIButton = {
let button = UIButton()
button.setTitle("Like", forState: .Normal)
button.titleLabel?.font = UIFont.systemFontOfSize(18)
button.setTitleColor(UIColor.darkGrayColor(), forState: .Normal)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
let hireButton: UIButton = {
let button = UIButton()
button.setTitle("Hire", forState: .Normal)
button.titleLabel?.font = UIFont.systemFontOfSize(18)
button.setTitleColor(UIColor.darkGrayColor(), forState: .Normal)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
let messageButton: UIButton = {
let button = UIButton()
button.setTitle("Message", forState: .Normal)
button.titleLabel?.font = UIFont.systemFontOfSize(18)
button.setTitleColor(UIColor.darkGrayColor(), forState: .Normal)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
let stackView: UIStackView = {
let sv = UIStackView()
sv.axis = UILayoutConstraintAxis.Horizontal
sv.alignment = UIStackViewAlignment.Center
sv.distribution = UIStackViewDistribution.FillEqually
sv.translatesAutoresizingMaskIntoConstraints = false;
return sv
}()
override init(frame: CGRect) {
super.init(frame: frame)
addViews()
}
func addViews(){
backgroundColor = UIColor.blackColor()
addSubview(profileImageButton)
addSubview(nameLabel)
addSubview(distanceLabel)
addSubview(pricePerHourLabel)
addSubview(ratingLabel)
addSubview(showCaseImageView)
addSubview(likesLabel)
addSubview(topSeparatorView)
addSubview(bottomSeparatorView)
// Stack View
addSubview(likeButton)
addSubview(messageButton)
addSubview(hireButton)
addSubview(stackView)
profileImageButton.leftAnchor.constraintEqualToAnchor(leftAnchor, constant: 5).active = true
profileImageButton.topAnchor.constraintEqualToAnchor(topAnchor, constant: 10).active = true
profileImageButton.heightAnchor.constraintEqualToConstant(36).active = true
profileImageButton.widthAnchor.constraintEqualToConstant(36).active = true
nameLabel.leftAnchor.constraintEqualToAnchor(profileImageButton.rightAnchor, constant: 5).active = true
nameLabel.centerYAnchor.constraintEqualToAnchor(profileImageButton.centerYAnchor, constant: -8).active = true
nameLabel.rightAnchor.constraintEqualToAnchor(pricePerHourLabel.leftAnchor).active = true
distanceLabel.leftAnchor.constraintEqualToAnchor(nameLabel.leftAnchor).active = true
distanceLabel.centerYAnchor.constraintEqualToAnchor(profileImageButton.centerYAnchor, constant: 8).active = true
distanceLabel.widthAnchor.constraintEqualToConstant(300)
pricePerHourLabel.rightAnchor.constraintEqualToAnchor(rightAnchor, constant: -10).active = true
pricePerHourLabel.centerYAnchor.constraintEqualToAnchor(nameLabel.centerYAnchor).active = true
// Distance depeneded on the priceLabel and distance Label
ratingLabel.rightAnchor.constraintEqualToAnchor(pricePerHourLabel.rightAnchor).active = true
ratingLabel.centerYAnchor.constraintEqualToAnchor(distanceLabel.centerYAnchor).active = true
showCaseImageView.topAnchor.constraintEqualToAnchor(profileImageButton.bottomAnchor, constant: 10).active = true
showCaseImageView.widthAnchor.constraintEqualToAnchor(widthAnchor).active = true
showCaseImageView.heightAnchor.constraintEqualToConstant(UIScreen.mainScreen().bounds.width - 20).active = true
likesLabel.topAnchor.constraintEqualToAnchor(showCaseImageView.bottomAnchor, constant: 10).active = true
likesLabel.leftAnchor.constraintEqualToAnchor(profileImageButton.leftAnchor).active = true
topSeparatorView.topAnchor.constraintEqualToAnchor(likesLabel.bottomAnchor, constant: 10).active = true
topSeparatorView.widthAnchor.constraintEqualToAnchor(widthAnchor).active = true
topSeparatorView.heightAnchor.constraintEqualToConstant(0.5).active = true
stackView.addArrangedSubview(likeButton)
stackView.addArrangedSubview(hireButton)
stackView.addArrangedSubview(messageButton)
stackView.topAnchor.constraintEqualToAnchor(topSeparatorView.bottomAnchor, constant: 4).active = true
stackView.widthAnchor.constraintEqualToAnchor(widthAnchor).active = true
stackView.centerXAnchor.constraintEqualToAnchor(centerXAnchor).active = true
bottomSeparatorView.topAnchor.constraintEqualToAnchor(stackView.bottomAnchor, constant: 4).active = true
bottomSeparatorView.widthAnchor.constraintEqualToAnchor(widthAnchor).active = true
bottomSeparatorView.heightAnchor.constraintEqualToConstant(0.5).active = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}

Answer 3

Su problema radica aquí. En su viewDidLoad() , está registrando su celda de collectionView dos veces. Está registrando la celda de collectionview en su clase de celda personalizada en la primera línea y luego en la segunda línea la está registrando en la clase UICollectionViewCell .

 collectionView.registerClass(MyCollectionViewCell.self, forCellWithReuseIdentifier: cellReuseIdentifier)
collectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "collectionCell")

Simplemente quite la segunda línea y su código debería funcionar.

Answer 4

override func awakeFromNib() {
super.awakeFromNib()
let overlayView = UIView()
overlayView.backgroundColor = UIColor.red
overlayView.frame = CGRect(x: 10, y: (350/2) - 50, width: 100, height: 100)
self.addSubview(overlayView)
}