如何以編程方式創建UICollectionViewCell

我試圖以編程方式創建UICollectionView。我需要在單元格內添加標籤，所以我創建了CollectionViewCell類。如何以編程方式創建UICollectionViewCell

這是類：

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") 
    } 
}

這是的CollectionView實現類：

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) 
    } 

}

錯誤發生時，細胞產生：

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

的錯誤是：無法將類型'UICollectionViewCell'（0x1033cc820）的值轉換爲'CollectionViewProgramatically.MyCollectionViewCell'（0x1015a4f88）。

我很樂意收到您的幫助。

來源

2016-09-11 s_s

你的問題在於此。在viewDidLoad()中，您正在註冊您的collectionView單元格兩次。您正在將collectionView的單元格註冊到您的自定義單元格類的第一行，然後在第二行註冊到類UICollectionViewCell。

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

只需刪除第二行，您的代碼應該可以工作。

來源

2016-09-11 17:51:26 ebby94

嘗試複製並粘貼此代碼到您的Xcode，它應該工作

// 
// 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") 
    } 

}

來源

2016-09-11 17:55:39

要了解如何使用閉包來創建對象，隨意參考這篇文章，https://blog.bobthedeveloper.io/swift-lazy-initialization-with-closures-a9ef6f6312c –

我改變Bob Lee answer爲迅速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") 
    } 

}

來源

2017-12-02 08:27:40

如何以編程方式創建UICollectionViewCell

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