Swift

1，下面代码创建并弹出一个告警框，并带有“取消”“确定”两个按钮

（注：自IOS8起，建议使用UIAlertController）

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class ViewController: UIViewController{     override func viewDidLoad() {         super.viewDidLoad()           var alertView = UIAlertView()         alertView.title = "系统提示"         alertView.message = "您确定要离开hangge.com吗？"         alertView.addButtonWithTitle("取消")         alertView.addButtonWithTitle("确定")         alertView.cancelButtonIndex=0         alertView.delegate=self;         alertView.show()     }       func alertView(alertView:UIAlertView, clickedButtonAtIndex buttonIndex: Int){         if(buttonIndex==alertView.cancelButtonIndex){             println("点击了取消")         }         else         {             println("点击了确认")         }     } }

2，告警框有下面4种样式
Default：默认样式
PlainTextInput：带输入框的告警框
SecureTextInput：带密码框的告警框
LoginAndPasswordInput：带输入框和密码框的告警框

下面是一个使用输入框和密码框的告警框样例：

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import UIKit   class ViewController: UIViewController {       var alertView = UIAlertView()           override func viewDidLoad() {         super.viewDidLoad()                   alertView.title = "系统登录"         alertView.message = "请输入用户名和密码！"         alertView.addButtonWithTitle("取消")         alertView.addButtonWithTitle("确定")         alertView.cancelButtonIndex=0         alertView.delegate=self;         alertView.alertViewStyle = UIAlertViewStyle.LoginAndPasswordInput         alertView.show()     }           func alertView(alertView:UIAlertView, clickedButtonAtIndex buttonIndex: Int){         if(buttonIndex==alertView.cancelButtonIndex){             println("点击了取消")         }         else         {             let name = alertView.textFieldAtIndex(0)             let password = alertView.textFieldAtIndex(1)             println("用户名是：(name!.text) 密码是：(password!.text)")         }     }       override func didReceiveMemoryWarning() {         super.didReceiveMemoryWarning()     } }