ios - Swift - 如何检查 TableView 是否为空

Question

所以我正在制作这个待办事项列表应用程序。这个应用程序有本地通知，但我只希望它们在 tableview 为空时弹出。简而言之:如何检查 tableview 是否为空？

这是我当前的代码:

import UIKit

class FirstViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {


@IBOutlet var tblTasks : UITableView!
@IBOutlet weak var countLbl: UILabel!
 var localNotification = UILocalNotification()

//For persisting data
let defaults = NSUserDefaults.standardUserDefaults()

override func viewDidLoad() {
    super.viewDidLoad()
    self.tblTasks.reloadData()


    // localNotification.alertAction = "Je hebt nog taken die gedaan moeten worden!"
    localNotification.alertBody = "Je hebt nog taken die gedaan moeten worden! Namelijk nog \(updateCount)"
    localNotification.timeZone = NSTimeZone.localTimeZone()

    localNotification.fireDate = NSDate(timeIntervalSinceNow: 10)
    UIApplication.sharedApplication().scheduleLocalNotification(localNotification)

}

override func viewWillAppear(animated: Bool) {
    self.tblTasks.reloadData()
}

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


func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
    return taskMgr.tasks.count

}

//Define how our cells look - 2 lines a heading and a subtitle
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{
    let cell: UITableViewCell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "Default Tasks")

    //Assign the contents of our var "items" to the textLabel of each cell
    cell.textLabel!.text = taskMgr.tasks[indexPath.row].name
    cell.detailTextLabel!.text = taskMgr.tasks[indexPath.row].description
    cell.backgroundColor = UIColor.clearColor()

    return cell

}

func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath){

    if (editingStyle == UITableViewCellEditingStyle.Delete){

        taskMgr.removeTask(indexPath.row)
        tblTasks.reloadData()
    }

}

谁能帮帮我？谢谢 ;)

Answer 1

在 Swift 3 中:

if tableView.visibleCells.isEmpty {
    //tableView is empty. You can set a backgroundView for it.
} else {
    //do something
}