Question

我对数据数组有问题，在此数据数组中，我发送了6张图像的名称，以便稍后将它们加载到CollectionView中，这6张图像加载得很好，没有任何问题，但是当我添加String时值发送给我，这是一个空的错误：

这是我的课程，我的数据数组在哪里：

 import UIKit

class HBook{
    var imagenB: UIImage!
    var estatus: String!

    init(estatus: String, imagenB: UIImage) {

        self.estatus = estatus
        self.imagenB = imagenB
    }

    class func getData() -> [HBook]{

        let rawData = [
            ["imagenB":"book1"],
            ["imagenB":"book2"],
            ["imagenB":"book3"],
            ["imagenB":"book4"],
            ["imagenB":"book5"],
            ["imagenB":"book6"],
            ["estatus":"No reservado"]
        ]

        var hbook:[HBook] = []

        for item in rawData{
            hbook.append(HBook(estatus: item["estatus"]!, imagenB: UIImage(named: item["imagenB"]!)!))   
        }
        return hbook
    }
}

我打印数据数组以查看哪个变量为空，但显然所有变量都有一个赋值：

我不知道为什么要发送一个空值。

此信息是在另一个具有CollectionView和Label的类中检索的，我传递信息的方法在cellForItemAt方法中：

class DetailViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {

    @IBOutlet weak var contenedorCollection: UIView!
    @IBOutlet weak var myCollection: UICollectionView!
    @IBOutlet weak var pages: UIPageControl!
    @IBOutlet weak var estatus: UILabel!

    var hbook = HBook.getData()
    var nombreH = ""

    override func viewDidLoad() {
        super.viewDidLoad()
        pages.numberOfPages = hbook.count
        self.title = nombreH

    }

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

    func numberOfSections(in collectionView: UICollectionView) -> Int {
        return 1
    }

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

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! CellCollectionViewCell

        cell.imageview.image = hbook[indexPath.row].imagenB
        estatus.text = hbook[indexPath.row].estatus
        return cell
    }

Answer 1

我认为问题出在数据类中。请用下面的代码替换您的HBook类，它将在不作任何进一步更改的情况下起作用：

class HBook{
var imagenB: UIImage?
var estatus: String?

init(estatus: String? = nil, imagenB: UIImage? = nil) {

    self.estatus = estatus
    self.imagenB = imagenB
}

class func getData() -> [HBook]{

    let rawData = [
        ["imagenB":"book1","estatus":"No reservado"],
        ["imagenB":"book2","estatus":"No reservado"],
        ["imagenB":"book3","estatus":"No reservado"],
        ["imagenB":"book4","estatus":"No reservado"],
        ["imagenB":"book5","estatus":"No reservado"],
        ["imagenB":"book6","estatus":"No reservado"]
    ]

    var hbook:[HBook] = []

    for item in rawData{
        if let image = item["itemnB"]{
            hbook.append(HBook(estatus: item["estatus"], imagenB:UIImage(named:image)))
        }else{
            hbook.append(HBook(estatus: item["estatus"]))
        }
    }
    return hbook
}

}

致命错误：展开可选值时意外发现nil

1 个答案: