Question

我在尝试以编程方式创建动态原型单元时遇到问题。这是我第一次尝试这种方法。我总是通过故事板创建它们。

我的ViewController.swift文件包含以下内容

var noteListTableView: UITableView = UITableView()


noteListTableView.frame.origin.x = 0.0
noteListTableView.frame.origin.y = kNAV_BAR_HEIGHT
noteListTableView.frame.size.width = kDEVICE_WIDTH
noteListTableView.frame.size.height = kDEVICE_HEIGHT - kNAV_BAR_HEIGHT
noteListTableView.dataSource = self
noteListTableView.delegate = self
self.view.addSubview(noteListTableView)

同样在文件中，我已经包含了相应的TableView委托和数据源函数

func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

    return GlobalDataController.notesDB.count

}

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    var aNote: NoteItem = GlobalDataController.notesDB[indexPath.row] as NoteItem

    if var cell: NoteListTVCell = noteListTableView.dequeueReusableCellWithIdentifier(kReuseCellNoteList) as? NoteListTVCell {

        cell.noteTitle.text = "Title"
        cell.noteContentSummary.text = "Content Summary"
        cell.noteDate.text = "May 20"

            return cell

        }
    else{

        var cell: NoteListTVCell = NoteListTVCell(style: UITableViewCellStyle.Default, reuseIdentifier: kReuseCellNoteList)

        cell.noteTitle.text = "Title"
        cell.noteContentSummary.text = "Content Summary"
        cell.noteDate.text = "May 20"

        return cell

    }

}

（1）IF-STATEMENT似乎总是失败，这就是为什么我按照我在网上为Obj-C找到的一些例子添加了else语句。

（2）当ELSE被触发时，程序总是崩溃，试图分配单元格。*值，说它遇到了零值。

任何想法？

编辑：NoteListTVCell class NoteListTVell：UITableViewCell {

    var noteTitle: UILabel!
    var noteContentSummary: UILabel!
    var noteDate: UILabel!

    var cellMargin: CGFloat = kPadding * 3

    override func awakeFromNib() {
        super.awakeFromNib()


        noteTitle = UILabel(frame: CGRect(x: cellMargin, y: kPadding, width: kDEVICE_WIDTH - cellMargin - kPadding, height: 30.0))
        noteTitle.backgroundColor = kColorTransparent
        noteTitle.font = UIFont(name: kFont02, size: 20.0)
        noteTitle.textColor = Scripts.hexColor(0x000000, alpha: 0.8)
        noteTitle.text = "Title"
        self.addSubview(noteTitle)

        /* Note Content Summary
        -----------------------------------------------------------------------------------------*/
        var noteContentSummaryY: CGFloat = noteTitle.frame.origin.y + noteTitle.frame.size.height

        noteContentSummary = UILabel(frame: CGRect(x: cellMargin, y: noteContentSummaryY, width: kDEVICE_WIDTH - cellMargin - kPadding, height: 20.0))
        noteContentSummary.backgroundColor = kColorTransparent
        noteContentSummary.font = UIFont(name: kFont02, size: 14.0)
        noteContentSummary.textColor = Scripts.hexColor(0x000000, alpha: 0.4)
        noteContentSummary.text = "This is a summary..."
        self.addSubview(noteContentSummary)

        /* Note Date
        -----------------------------------------------------------------------------------------*/
        noteDate = UILabel(frame: CGRect(x: kDEVICE_WIDTH - 100.0 - kPaddingx2, y: kPadding, width: 100.0, height: 20.0))
        noteDate.backgroundColor = kColorTransparent
        noteDate.font = UIFont(name: kFont02, size: 10.0)
        noteDate.textColor = Scripts.hexColor(kColorThemeBlue, alpha: 1.0)
        noteDate.textAlignment = NSTextAlignment.Right
        noteDate.text = "May 8, 2:14 AM"
        self.addSubview(noteDate)

    }

    override func setSelected(selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)

        // Configure the view for the selected state
    }

}

Answer 1

您需要在viewDidLoad注册自定义tableViewCell类：

notelistTableView.registerClass(NoteListTVCell.self, forCellReuseIdentifier: kReuseCellNoteList)

Documentation

在InterfaceBuilder中设计原型时，这是自动完成的。在代码中设计单元格时需要它。

Answer 2

您没有覆盖自定义单元格中的init方法，但无论如何，如果您不提供，它将调用super init方法。将您的单元初始化代码放在init方法中而不是awakeFromNib方法。

请尝试以下操作。

    required init(coder aDecoder: NSCoder) {

            super.init(coder: aDecoder)
    }


    override init(style: UITableViewCellStyle, reuseIdentifier: String!) {

         super.init(style: style, reuseIdentifier: reuseIdentifier)
         //Do your cell set up
        noteTitle = UILabel(frame: CGRect(x: cellMargin, y: kPadding, width: kDEVICE_WIDTH - cellMargin - kPadding, height: 30.0))
        noteTitle.backgroundColor = kColorTransparent
        noteTitle.font = UIFont(name: kFont02, size: 20.0)
        noteTitle.textColor = Scripts.hexColor(0x000000, alpha: 0.8)
        noteTitle.text = "Title"
        self.addSubview(noteTitle)

        /* Note Content Summary
        -----------------------------------------------------------------------------------------*/
        var noteContentSummaryY: CGFloat = noteTitle.frame.origin.y + noteTitle.frame.size.height

        noteContentSummary = UILabel(frame: CGRect(x: cellMargin, y: noteContentSummaryY, width: kDEVICE_WIDTH - cellMargin - kPadding, height: 20.0))
        noteContentSummary.backgroundColor = kColorTransparent
        noteContentSummary.font = UIFont(name: kFont02, size: 14.0)
        noteContentSummary.textColor = Scripts.hexColor(0x000000, alpha: 0.4)
        noteContentSummary.text = "This is a summary..."
        self.addSubview(noteContentSummary)

        /* Note Date
        -----------------------------------------------------------------------------------------*/
        noteDate = UILabel(frame: CGRect(x: kDEVICE_WIDTH - 100.0 - kPaddingx2, y: kPadding, width: 100.0, height: 20.0))
        noteDate.backgroundColor = kColorTransparent
        noteDate.font = UIFont(name: kFont02, size: 10.0)
        noteDate.textColor = Scripts.hexColor(kColorThemeBlue, alpha: 1.0)
        noteDate.textAlignment = NSTextAlignment.Right
        noteDate.text = "May 8, 2:14 AM"
        self.addSubview(noteDate)
    }

在viewDidLoad

中执行此操作

override func viewDidLoad() {
        super.viewDidLoad()
        noteListTableView = UITableView(frame: self.view.frame, style: UITableViewStyle.Plain)
        noteListTableView.dataSource = self
        noteListTableView.delegate = self
        self.view.addSubview(noteListTableView)
        noteListTableView.registerClass(NoteListTVCellTableViewCell.self, forCellReuseIdentifier: kReuseCellNoteList)
        // Do any additional setup after loading the view, typically from a nib.
    }

以编程方式创建自定义动态原型单元格

2 个答案: