IOS8后虽然出了新的控制器UIAlertController，但之前的UIAlertView，UIActionSheet依然可以使用。
一、初始化方法
- (instancetype)initWithTitle:(NSString *)title delegate:(id<UIActionSheetDelegate>)delegate cancelButtonTitle:(NSString *)cancelButtonTitle destructiveButtonTitle:(NSString *)destructiveButtonTitle otherButtonTitles:(NSString *)otherButtonTitles, ...;
参数说明：
title：视图标题
delegate：设置代理
cancelButtonTitle：取消按钮的标题
destructiveButtonTitle：特殊标记的按钮的标题
otherButtonTitles：其他按钮的标题
二、常用方法和属性介绍
@property(nonatomic,copy) NSString *title;
设置标题
@property(nonatomic) UIActionSheetStyle actionSheetStyle;
设置风格，枚举如下：
typedef NS_ENUM(NSInteger, UIActionSheetStyle) {
UIActionSheetStyleAutomatic = -1,
UIActionSheetStyleDefault = UIBarStyleDefault,
UIActionSheetStyleBlackTranslucent = UIBarStyleBlackTranslucent,
UIActionSheetStyleBlackOpaque = UIBarStyleBlackOpaque,
};
- (NSInteger)addButtonWithTitle:(NSString *)title;
添加一个按钮，会返回按钮的索引
- (NSString *)buttonTitleAtIndex:(NSInteger)buttonIndex;
获取按钮标题
@property(nonatomic,readonly) NSInteger numberOfButtons;
获取按钮数量
@property(nonatomic) NSInteger cancelButtonIndex;
设置取消按钮的索引值
@property(nonatomic) NSInteger destructiveButtonIndex;
设置特殊标记
@property(nonatomic,readonly,getter=isVisible) BOOL visible;
视图当前是否可见
下面是几种弹出方式，会根据风格不同展现不同的方式
- (void)showFromToolbar:(UIToolbar *)view;
- (void)showFromTabBar:(UITabBar *)view;
- (void)showFromBarButtonItem:(UIBarButtonItem *)item animated:(BOOL)animated ;
- (void)showFromRect:(CGRect)rect inView:(UIView *)view animated:(BOOL)animated ;
- (void)showInView:(UIView *)view;
- (void)dismissWithClickedButtonIndex:(NSInteger)buttonIndex animated:(BOOL)animated;
使用代码将视图收回
三、UIActionSheet代理方法
- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex;
点击按钮时触发的方法
- (void)willPresentActionSheet:(UIActionSheet *)actionSheet;
视图将要弹出时触发的方法
- (void)didPresentActionSheet:(UIActionSheet *)actionSheet;
视图已经弹出式触发的方法
- (void)actionSheet:(UIActionSheet *)actionSheet willDismissWithButtonIndex:(NSInteger)buttonIndex;
点击按钮后，视图将要收回时触发的方法
- (void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex;
点击按钮后，视图已经收回时触发的方法