Question

在Objective-C的早期，我们在UIAlertView中使用了delegate：self，这样我们就可以在index ...中调用buttonclicked等方法，但现在在swift中我在哪里设置该委托？因为我的按钮点击索引方法没有被调用..

import UIKit

class ViewController:UIViewController,UITableViewDelegate,UITableViewDataSource,UIAlertViewDelegate{

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.
}
func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell!{
let cell :UITableViewCell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: nil)
cell.text = "HI \(indexPath.row)"
cell.detailTextLabel.text = "SWIFT"
return cell
}
func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int
{
 return 5
}

 func tableView(tableView: UITableView!, didSelectRowAtIndexPath indexPath: NSIndexPath!)
 {


   var alert = UIAlertController(title: "Demo", message: "You have selected row number\(indexPath.row)", preferredStyle: UIAlertControllerStyle.Alert)
    alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default, handler: nil))
    alert.addAction(UIAlertAction(title: "KILL", style: UIAlertActionStyle.Destructive, handler: nil))
    alert.addAction(UIAlertAction(title: "PUNE", style: UIAlertActionStyle.Default, handler: nil))
    alert.addAction(UIAlertAction(title: "Mumbai", style: UIAlertActionStyle.Default, handler: nil))
    alert.addAction(UIAlertAction(title: "Kolkata", style: UIAlertActionStyle.Default, handler: nil))
    alert.addAction(UIAlertAction(title: "Chennai", style: UIAlertActionStyle.Default, handler: nil))

    self.presentViewController(alert, animated: true, completion: nil)


 }
func demoFunction (myName:NSString)
{
    NSLog("%@", "swapnil")
}

func alertView(alertView: UIAlertView!, clickedButtonAtIndex buttonIndex: Int)
{
    NSLog("%@", "YOU PRESSED OK" )
    switch (buttonIndex)
        {
        case 0:NSLog("%@", "YOU PRESSED OK" )
        case 1:NSLog("%@", "YOU PRESSED KILLER" )
        case 2:NSLog("%@", "YOU PRESSED PUNE" )
        case 3:NSLog("%@", "YOU PRESSED MUMBAI" )
        case 4:NSLog("%@", "YOU PRESSED KOLKATA" )
        case 5:NSLog("%@", "YOU PRESSED Chennai" )
        default :NSLog("%@", "You have pressed default")

        }

}

}

Answer 1

您不应该使用委托方法，实际上UIAlertController不提供委派。

在您的情况下，您的警报措施应该是这样的：

alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler:    {(alert :UIAlertAction!) in
        println("YOU PRESSED OK")

        }))

以及每个动作等等！

Answer 2

UIAlertController未实现委托属性。它使用-addAction:的handler参数来处理按钮上的点击。以下是如何完成此操作的示例：

alert.addAction(UIAlertAction(title: "RandomTitle", style: UIAlertActionStyle.Default, handler:{(alert :UIAlertAction!) -> void in
    //Handle action here. 
    //You can also use the alert title property to differentiate between 
    //UIAlertActions and hand the same closure in to each one. E.i.

    if(action.title == "first option"){
        //handle when the user taps the "first option" button.
    }
}))

单击UIAlertViewDelegate中索引的按钮未被调用

2 个答案: