无法在 tableview Swift 中显示核心数据 [英] Can't show the core data in tableview Swift

问题描述

class showPageViewController: UIViewController, UITableViewDelegate, UITableViewDataSource  
{

@IBOutlet weak var tableView: UITableView!
var records : [Record] = []

func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}

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

    return records.count
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = UITableViewCell()
    return cell
}

func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath){
    let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext

    if editingStyle == .delete{
        let record = records[indexPath.row]
        context.delete(record)
        (UIApplication.shared.delegate as! AppDelegate).saveContext()
        do{
            records = try context.fetch(Record.fetchRequest())
        } catch{
            print("Failed")
        }
    }


}

override func viewWillAppear(_ animated: Bool) {
    getData()
    tableView.reloadData()
}

func getData(){
    let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
    do{
        records = try context.fetch(Record.fetchRequest())
    } catch{
        print("123")
    }
}


override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
}

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

大家好，我只是尝试在表格视图中显示核心数据，我已经将dataSource和delegate连接到ViewController，我确认核心数据中有一些数据，任何人都可以帮助我吗?谢谢

Hello everyone, I just tried to show the core data in table view, I already connect the dataSource and delegate to the ViewController, and I confirmed There are some data in core data, anyone can help me plz? thanks

推荐答案

两个大错误:

1. 您不能使用默认初始化程序 UITableViewCell() 创建单元格，您必须将其出列.

2. 您必须获取索引路径的数据源数组中的项目，并将属性值分配给单元格的标签.

1. You cannot create a cell with the default initializer UITableViewCell() you have to dequeue it.

2. You have to get the item in the data source array for the index path and assign a value of a property to a label of the cell.

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
    let record = records[indexPath.row]
    cell.textLabel!.text = record.<nameOfProperty>
    return cell
}

cell 是 Interface Builder 中指定的标识符.
是数据模型中的一个属性.

cell is the identifier specified in Interface Builder.
<nameOfProperty> is a property in your data model.

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