更新 TableView 单元格数据

Question

I'm new to Swift/Xcode and reached a problem with updating TableView cell data. I can't quite seem to find/implement the answer to this simple thing from any similar StackOverflow questions either.

I have an app that starts making an api call every 1 sec on a timer once a button is pressed but the problem is that when all tableview data gets loaded from an array with viewDidLoad() theres obviously no data to display in the label as no call has been made yet.

Once I press the button the data starts flowing but nothing appears in the label. I believe this is because the label needs to be updated upon every call in order to display the new data.

The data is also an NSAttributedString from HTML. Not sure if this is relevant though as it seems to work fine in test cell's outside of the tableview.

Essentially what I want to do is somehow call

    cell.cellLabelTwo.attributedText = tableData[indexPath.row].secondRowLabel

from the code shown below every time a new api call is made and update cellLabelTwo with the new % gain data.

struct MyData {
    var imageRow: UIImage
    var firstRowLabel: String
    var secondRowLabel: NSAttributedString
}

var tableData: [MyData] = []

override func viewDidLoad() {
    super.viewDidLoad()

    tableData = [
        MyData(imageRow: UIImage(named: "ada.png")!, firstRowLabel: "ADA/USDT", secondRowLabel: adaPercentGainString.htmlToAttributedString!)
    ]

}


func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return tableData.count
}


func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: "protoCellOne") as! TableViewCell

    cell.cellImageOne.image = tableData[indexPath.row].imageRow
    cell.cellLabelOne.text = tableData[indexPath.row].firstRowLabel
    cell.cellLabelTwo.attributedText = tableData[indexPath.row].secondRowLabel
    cell.cellLabelTwo.font = UIFont(name: "Helvetica Neue", size: 19)
    cell.cellLabelTwo.textAlignment = .right

    return cell

}

Edit: I have added @IBOutlet var tableView: UITableView! and connected it to View Controller, I've also assigned the tableview to datasource and delegate of View Controller. Adding the IB outlet seemed to be solution to this for many other people but it still not showing anything in the cell label...

Answer 1

You simply need to reload the table view after each API call.

tableView.reloadData()

This would be best called in a completion handler of your API call, but you don't provide your code where the API is called.

Reloading the data will call the delegate method cellForRowAt: for each cell, which is where you have the code that you want to run.