在Swift中设置UICollectionView单元格高度

Question

我正在尝试创建一个UICollectionView，每个单元格将根据单元格中的内容量具有不同的高度。我理解

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

调用

以在单元格出列时设置单个单元格大小。我正在研究细胞需要的高度

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell

但是我创建的变量没有保留在sizeForItemAtIndexPath中。

我哪里错了？完整的课程如下。我一直在努力让这个工作，所以可能会有一些不必要的代码浮动。感谢任何帮助。

import UIKit
var cellHeight: CGFloat = 0.0
class ViewController: UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {

    var collectionView: UICollectionView?
    internal var thisCellHeight: CGFloat = CGFloat()



    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        let screenSize: CGRect = UIScreen.mainScreen().bounds
        let screenWidth = screenSize.width
        let screenHeight = screenSize.height


        var thisWidth = screenWidth - 10

        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
        layout.sectionInset = UIEdgeInsets(top: 70, left: 10, bottom: 10, right: 10)
        layout.itemSize = CGSize(width: thisWidth, height: 180)
        collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
        //collectionView!.backgroundView?.backgroundColor = UIColor.blueColor()
        collectionView!.dataSource = self
        collectionView!.delegate = self
        collectionView!.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
        collectionView!.backgroundColor = hexStringToUIColor("#15ADFF")
        self.view.addSubview(collectionView!)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 14
    }

    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {


        println("Index Path Number: \(indexPath)")
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as UICollectionViewCell
        cell.backgroundColor = UIColor.whiteColor()


        var typeLabel = UILabel(frame: CGRectMake(10, 0, 200, 21))
        typeLabel.text = "Card Type"
        typeLabel.font = typeLabel.font.fontWithSize(20)
        cell.addSubview(typeLabel)

        var titleLabel = UILabel(frame: CGRectMake(10, 25, 250, 21))

        titleLabel.text = "This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title. This Is The Article Title."
        titleLabel.font = titleLabel.font.fontWithSize(20)
        titleLabel.numberOfLines = 0
        titleLabel.sizeToFit()
        thisCellHeight = CGFloat(titleLabel.frame.height)
        println("The title text is \(cellHeight) high")
        cell.addSubview(titleLabel)

        var authorLabel = UILabel(frame: CGRectMake(10, thisCellHeight + 30, 200, 21))
        authorLabel.text = "This Is The Article Author"
        authorLabel.font = authorLabel.font.fontWithSize(15)
        cellHeight = cellHeight + CGFloat(authorLabel.frame.height)
        println("After article added height \(cellHeight) high")
        cell.addSubview(authorLabel)

        var timestampLabel = UILabel(frame: CGRectMake(10, thisCellHeight + 50, 200, 21))
        timestampLabel.text = "This Is The Timestamp"
        timestampLabel.font = timestampLabel.font.fontWithSize(15)
        cellHeight = cellHeight + CGFloat(timestampLabel.frame.height)
        println("After timestamp added height \(cellHeight) high")
        cell.addSubview(timestampLabel)

        return cell
    }

    func hexStringToUIColor (hex:String) -> UIColor {
        var cString:String = hex.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet() as NSCharacterSet).uppercaseString

        if (cString.hasPrefix("#")) {
            cString = cString.substringFromIndex(advance(cString.startIndex, 1))
        }

        if (countElements(cString) != 6) {
            return UIColor.grayColor()
        }

        var rgbValue:UInt32 = 0
        NSScanner(string: cString).scanHexInt(&rgbValue)

        return UIColor(
            red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
            green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
            blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
            alpha: CGFloat(1.0)
        )
    }

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



        println("Passed height = \(cellHeight)")

        return CGSizeMake(270, 300)


    }



}