iOS8中的UIAlertView和UIActionSheet已经都被UIAlertViewController代替了,所以,本篇blog就来探讨下如何用swift生成提示框。
我们先来看一下Apple的UIAlertController的文档:
import Foundationimport UIKit//// UIAlertController.h// UIKit//// Copyright (c) 2014 Apple Inc. All rights reserved.//@availability(iOS, introduced=8.0)enum UIAlertActionStyle : Int {case Defaultcase Cancelcase Destructive}@availability(iOS, introduced=8.0)enum UIAlertControllerStyle : Int {case ActionSheetcase Alert}@availability(iOS, introduced=8.0)class UIAlertAction : NSObject, NSCopying {convenience init(title: String, style: UIAlertActionStyle, handler: ((UIAlertAction!) -> Void)!)var title: String { get }var style: UIAlertActionStyle { get }var enabled: Bool}@availability(iOS, introduced=8.0)class UIAlertController : UIViewController {convenience init(title: String?, message: String?, preferredStyle: UIAlertControllerStyle)func addAction(action: UIAlertAction)var actions: [AnyObject] { get }func addTextFieldWithConfigurationHandler(configurationHandler: ((UITextField!) -> Void)!)var textFields: [AnyObject]? { get }var title: String?var message: String?var preferredStyle: UIAlertControllerStyle { get }}
我们可以看到UIAlertController的style有两个,一个是ActionSheet,一个是Alert,而AlertActionStyle有3个: Default,,Cancel, Destructive;所以我们新建Alert时可以这样:
var alert: UIAlertController = UIAlertController(title:nil, message:"您输入的电话号码有误,请检查后重新输入",preferredStyle:UIAlertControllerStyle.Alert)或者
var alert: UIAlertController = UIAlertController(title: nil, message:"test", preferredStyle: UIAlertControllerStyle.ActionSheet)
接下来我们来给Alert添加action,从文档中可以看到AlertAction有init函数,
我们来新建3个actions
var saveAction = UIAlertAction(title: "Save", style: .Default, handler:{(alerts: UIAlertAction!) -> Void inprintln("File saved")})var deleteAction = UIAlertAction(title: "Delete", style: .Default, handler:{(alerts: UIAlertAction!) -> Void inprintln("File delete")})var cancelAction = UIAlertAction(title: "Cancel", style: .Cancel, handler:{(alerts: UIAlertAction!) -> Void inprintln("Cancelled")})注意到handler中用到了一个closure
然后给我们的alertcontroller添加actions,并把它显示出来
alert.addAction(saveAction)alert.addAction(deleteAction)alert.addAction(cancelAction)self.presentViewController(alert, animated: true, completion: nil)我们也可以这样添加action
alert.addAction(UIAlertAction(title: "确定", style: .Destructive, handler: {action in switch action.style{case .Default:println("ok")case .Cancel:println("cancel")case .Destructive:println("Destructive")}}))接下来运行一下看看我们的alertController是什么样子的吧。
Tips:
如果style是cancel 那么字体会变粗;如果是destructive,字体会显示红色。
不曾见谁。则见朵花儿闪下来,好一惊。