ios - Swift 文件包含一个 Imageview 的多个 TableView 代码

Question

我的应用程序中有多个表格 View ，当用户单击某个单元格时，一个 View Controller 上会显示特定图像。因为我有很多 TableView ，所以我想将多个 TableView 的代码放在一个文件中。我现在的代码打开第一个“心脏”表格 View ，并且可以单击单元格来查看图片，但对于其他单元格，应用程序崩溃；即使代码编译。我不明白为什么，但我确信这很简单。我的代码如下:

    import UIKit
import GoogleMobileAds

///You are using this class a UIViewCOntroller in storyBoard bbut hadnt provided **tablelist: UIViewController**
///This is Necessary in case when you are going to assign it to a UIVIewController
class adultprotocols: UIViewController, UITableViewDataSource, UITableViewDelegate, GADBannerViewDelegate {

    var bannerView: GADBannerView!

    override func viewDidLoad(){
        super.viewDidLoad()

        self.navigationController?.navigationBar.barTintColor = UIColor.black
        let textAttributes = [NSForegroundColorAttributeName:UIColor.red]
        navigationController?.navigationBar.titleTextAttributes = textAttributes



        ///You need to Sert datasource and Delegate as its not a TableViewController its just a Normal TableView
        self.cardiacTableView.dataSource = self
        self.cardiacTableView.delegate = self




        self.view.backgroundColor = UIColor.black


        //---------ADS-------------------------------------------
        // In this case, we instantiate the banner with desired ad size.
        bannerView = GADBannerView(adSize: kGADAdSizeBanner)

        addBannerViewToView(bannerView)
    }


    func addBannerViewToView(_ bannerView: GADBannerView) {
        bannerView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(bannerView)
        view.addConstraints(
            [NSLayoutConstraint(item: bannerView,
                                attribute: .bottom,
                                relatedBy: .equal,
                                toItem: bottomLayoutGuide,
                                attribute: .top,
                                multiplier: 1,
                                constant: 0),
             NSLayoutConstraint(item: bannerView,
                                attribute: .centerX,
                                relatedBy: .equal,
                                toItem: view,
                                attribute: .centerX,
                                multiplier: 1,
                                constant: 0)
            ])


        bannerView.adUnitID = "ca-app-pub-3940256099942544/2934735716"
        bannerView.rootViewController = self
        bannerView.load(GADRequest())
    }




    //--------------------------LIST Specs-------------------------------------------------------//

    let cardiac = ["one", "twoasdg", "Cowasdasd", "Mulvadasdal"]
    let respiratory = ["one", "AsdaSD", "asdasdadad"]
    let trauma = ["one", "two", "three"]
    let ams = ["one","two"]

    ///You did not connected a outlet of tableView
    ///as its not a tableViewController just a TableView so it should be Connected
    @IBOutlet weak var animalTableView: UITableView!

    @IBOutlet weak var cardiacTableView: UITableView!

    @IBOutlet weak var respiratoryTableView: UITableView!


    ///Set elements in cell
    func tableView(  _ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
    {
        let cell = tableView.dequeueReusableCell(withIdentifier: "adultcardiaclist"/*Identifier*/, for: indexPath)
        cell.textLabel?.text = cardiac[indexPath.row]
        // FONT STYLE
        cell.textLabel?.textColor = UIColor.white
        cell.detailTextLabel?.font = UIFont.boldSystemFont(ofSize: 30.0)
        cell.textLabel?.textAlignment = .center
        self.cardiacTableView.backgroundColor = UIColor.clear
        cell.textLabel?.backgroundColor = UIColor.black

        return cell
    }
    func resptableView(  _ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
    {
        let cell = tableView.dequeueReusableCell(withIdentifier: "adultrespiratorylist"/*Identifier*/, for: indexPath)
        cell.textLabel?.text = respiratory[indexPath.row]
        // FONT STYLE
        cell.textLabel?.textColor = UIColor.white
        cell.detailTextLabel?.font = UIFont.boldSystemFont(ofSize: 30.0)
        cell.textLabel?.textAlignment = .center
        self.respiratoryTableView.backgroundColor = UIColor.clear
        cell.textLabel?.backgroundColor = UIColor.black

        return cell
    }
    func traumatableView(  _ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
    {
        let cell = tableView.dequeueReusableCell(withIdentifier: "adulttraumalist"/*Identifier*/, for: indexPath)
        cell.textLabel?.text = cardiac[indexPath.row]
        // FONT STYLE
        cell.textLabel?.textColor = UIColor.white
        cell.detailTextLabel?.font = UIFont.boldSystemFont(ofSize: 30.0)
        cell.textLabel?.textAlignment = .center
        self.cardiacTableView.backgroundColor = UIColor.clear
        cell.textLabel?.backgroundColor = UIColor.black

        return cell
    }
    func amstableView(  _ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
    {
        let cell = tableView.dequeueReusableCell(withIdentifier: "adultamslist"/*Identifier*/, for: indexPath)
        cell.textLabel?.text = cardiac[indexPath.row]
        // FONT STYLE
        cell.textLabel?.textColor = UIColor.white
        cell.detailTextLabel?.font = UIFont.boldSystemFont(ofSize: 30.0)
        cell.textLabel?.textAlignment = .center
        self.cardiacTableView.backgroundColor = UIColor.clear
        cell.textLabel?.backgroundColor = UIColor.black

        return cell
    }


    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return cardiac.count
    }
    func resptableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return respiratory.count
    }
    func traumatableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return trauma.count
    }
    func amstableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return ams.count
    }


    //--------------------------Cardiac List--------------------
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
    {
        ///Right way here
        ///You can easily manage using this
        let Vc = self.storyboard?.instantiateViewController(withIdentifier: "imageViewController") as! imageViewController

        ///Here you have written four Animal names in Array
        ///So There is going to four case 0,1,2,3 and a default case
        switch indexPath.row
        {
        case 0:
            Vc.passedImage = UIImage.init(named: "image1")!
            self.navigationController?.pushViewController(Vc, animated: true)
            break;
        case 1:
            Vc.passedImage = UIImage.init(named: "image2")!
            self.navigationController?.pushViewController(Vc, animated: true)
            break;
        case 2:
            Vc.passedImage = UIImage.init(named: "image3")!
            self.navigationController?.pushViewController(Vc, animated: true)
            break;
        case 3:
            Vc.passedImage = UIImage.init(named: "image1")!
            self.navigationController?.pushViewController(Vc, animated: true)
            break;
        default:
            Vc.passedImage = UIImage.init(named: "image2")!
            self.navigationController?.pushViewController(Vc, animated: true)
        }
    }

    func resptableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
    {
        ///Right way here
        ///You can easily manage using this
        let Bv = self.storyboard?.instantiateViewController(withIdentifier: "imageViewController") as! imageViewController

        ///Here you have written four Animal names in Array
        ///So There is going to four case 0,1,2,3 and a default case
        switch indexPath.row
        {
        case 0:
            Bv.passedImage = UIImage.init(named: "image1")!
            self.navigationController?.pushViewController(Bv, animated: true)
            break;
        case 1:
            Bv.passedImage = UIImage.init(named: "image2")!
            self.navigationController?.pushViewController(Bv, animated: true)
            break;
        case 2:
            Bv.passedImage = UIImage.init(named: "image3")!
            self.navigationController?.pushViewController(Bv, animated: true)
            break;
        case 3:
            Bv.passedImage = UIImage.init(named: "image1")!
            self.navigationController?.pushViewController(Bv, animated: true)
            break;
        default:
            Bv.passedImage = UIImage.init(named: "image2")!
            self.navigationController?.pushViewController(Bv, animated: true)
        }
    }

我是否错误地使用了“func tableview”“func resptableview”？

Answer 1

你的问题太模糊了。哪一行崩溃了，并显示什么错误消息？

我的猜测是，您由于使用强制展开(!)运算符而崩溃。我称其为“crash if nil”运算符，因为这就是它的作用。

您应该将目标 imageViewController 的 passedImage 属性设置为 Optional，并摆脱强制展开。然后编写你的 imageViewController 以便它处理 ImageView 为零的情况。

作为初学者，您应该完全避免使用强制展开运算符。我建议使用它的唯一一次是当 Xcode 将 IBOutlet 设置为强制解包可选时，因为您想立即知道您是否有一个损坏的 socket 链接，并且当它不让时崩溃你很早就知道这个问题了。

还要避免 as! 强制转换。这是另一种如果失败就会崩溃的情况。习惯使用 guard 语句或 if let 可选绑定(bind)。