如何在Swift中的Alert中向按钮添加操作

Question

我是初级程序员.我正在尝试向Alert上的按钮添加操作,但它不起作用.我只想测试警报按钮选项是否可以更改标签中的文本,但它不起作用.当然,我可以很好地看到警报和按钮,但点击按钮后没有任何反应.

@IBOutlet var statusLabelAlert : UILabel

var alertTest = UIAlertView()

@IBAction func alertButton(sender : AnyObject) {

    alertTest.message = "Select one!"
    alertTest.addButtonWithTitle("1st")
    alertTest.addButtonWithTitle("2nd")
    alertTest.addButtonWithTitle("3rd")
    alertTest.title = "Test Alert"
    alertTest.show()

}
func alertView(alertView: UIAlertView!, clickedButtonAtIndex buttonIndex: Int){
    switch buttonIndex{
    case 0:
        statusLabelAlert.text = "1st"
    case 1:
        statusLabelAlert.text = "2nd"
    case 2:
        statusLabelAlert.text = "3rd"
    default:
        statusLabelAlert.text = "error"
    }

}

Answer 1

你的clickedButtonAtIndex方法是否正在调用？设置断点并调试代码.您没有设置alertView的委托.

@IBOutlet var statusLabelAlert : UILabel

var alertTest = UIAlertView()
alertTest.delegate = self   //set the delegate of alertView

@IBAction func alertButton(sender : AnyObject) {

alertTest.message = "Select one!"
alertTest.addButtonWithTitle("1st")
alertTest.addButtonWithTitle("2nd")
alertTest.addButtonWithTitle("3rd")
alertTest.title = "Test Alert"
alertTest.show()

}
func alertView(alertView: UIAlertView!, clickedButtonAtIndex buttonIndex: Int){
switch buttonIndex{
case 0:
    statusLabelAlert.text = "1st"
case 1:
    statusLabelAlert.text = "2nd"
case 2:
    statusLabelAlert.text = "3rd"
default:
    statusLabelAlert.text = "error"
}

}