UIAlertController和UIAlertAction
1 @IBAction func showAlert() { 2 3 let alert = UIAlertController(title: "Hello World!", message: "This is my first app", preferredStyle: .Alert) 4 5 //1.默认按钮 6 let defaults = UIAlertAction(title: "Default", style: .Default, handler: nil) 7 alert.addAction(defaults) 8 9 //2.取消按钮 10 let cancel = UIAlertAction(title: "Cancel", style: .Cancel, handler: nil) 11 alert.addAction(cancel) 12 13 //3.红色警告按钮 14 let destructive = UIAlertAction(title: "Destructive", style: .Destructive, handler: nil) 15 alert.addAction(destructive) 16 17 presentViewController(alert, animated: true, completion: nil) 18 }
运行结果:
发现:UIAlertAction.Cancel 始终显示在最后一个。