CODEWITHSUNDEEP
iosuitableviewswift
MortalMan
MortalMan

Reputation: 2612

Creating a UITableView object crashes in Swift

I am making a to-do app in Swift, and I am trying to display the tasks using a UITableView. Users add a task, and press "Done". The UITableView is brought back to the front, and the app crashes. Here is my code:

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

    let cell: UITableViewCell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: nil) //crashes on this line
    cell.textLabel!.text = taskMgr.tasksArray[indexPath.row].name
    cell.detailTextLabel!.text = taskMgr.tasksArray[indexPath.row].desc

    return cell
}

Funny enough, this line works fine in another very similar app I quickly created. Could anyone please point me in the right direction? I am happy to add more detail if necessary.

Upvotes: 0

Views: 2282

Answers (3)

Ashish Kakkad
Ashish Kakkad

Reputation: 23882

Use reuse identifier

func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
    var cell:UITableViewCell = self.tblSwift.dequeueReusableCellWithIdentifier("cell") as UITableViewCell

    cell.textLabel.text = self.items[indexPath.row]
    return cell
}

With Detail Title

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

    var cell = tableView.dequeueReusableCellWithIdentifier("cell") as? UITableViewCell

    if cell == nil {
        cell = UITableViewCell(style: .Subtitle, reuseIdentifier: "cell")
    }
    cell!.textLabel.text = self.names[indexPath.row]
    cell!.detailTextLabel.text = self.emails[indexPath.row]
    return cell
}

Upvotes: 0

vichhai
vichhai

Reputation: 2568

I wrote like this:

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

    let cell:CustomCell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! CustomCell
    cell.lblText.text  = "Testing"
    return cell
}

Upvotes: 1

atreat
atreat

Reputation: 4403

You should refactor your code to take advantage of the performance of a UITableView. Your cells can be re-used instead of re-created each time they are displayed on screen.

To do this, you should remove the init method call of UITableViewCell. Instead replace it with: dequeueReusableCellWithIdentifier:forIndexPath:

New in iOS 6, the pattern is to register a TableViewCell subclass with the tableview with the reuse identifier. Then you can easily grab a re-usable cell with dequeReusableCellWithIdentifier:forindexPath:

In viewDidLoad or somewhere before the tableview datasource/delegate methods are called, you should make a call to register your cell subclass. registerClass:forCellReuseIdentifier:

For you, in Swift, you'll want to call:

tableview.registerClass(UITableViewCell.self, identifier:"MyReuseIdentifier")
// note there is also a method to register nibs

Then in the cellForRowAtIndexPath method:

tableView.dequeReusableCellWithIdentifier("MyReuseIdentifier", forIndexPath: indexPath)

Upvotes: 0

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