Swift 基本控件UIAlertView学习

 let 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){            print("点击了取消")        }        else        {            print("点击了确认")        }    }