引言

UIActionSheet继承于UIView（有关UIView的介绍请到《iOS组件之UIView详解》）。使用UIActionSheet类有一组关于如何进行给定任务的备选方案呈现给用户。也可以使用动作表，以提示用户进行确认，有潜在危险的动作。动作片包含一个可选的标题和一个或多个按钮，其中每一个对应于要采取的动作。

目录

// 初始化UIActionSheet上的button按钮

- (id)initWithTitle:(NSString *)title delegate:(id<UIActionSheetDelegate>)delegate cancelButtonTitle:(NSString *)cancelButtonTitle destructiveButtonTitle:(NSString *)destructiveButtonTitle otherButtonTitles:(NSString *)otherButtonTitles, ... ;

// 设置UIActionSheet代理

id<UIActionSheetDelegate> delegate;    // weak reference

// 设置UIActionSheet的title

NSString *title;

// 设置UIActionSheet的样式（默认为UIActionSheetStyleAutomatic）

UIActionSheetStyle actionSheetStyle;

// 通过按钮的title获取这个按钮在UIActionSheet上的下标

- (NSInteger)addButtonWithTitle:(NSString *)title;

// 通过下标获得按钮的title

- (NSString *)buttonTitleAtIndex:(NSInteger)buttonIndex;

// 获取按钮的总个数(只读)

NSInteger numberOfButtons;

// 获取取消按钮的下标

NSInteger cancelButtonIndex;

// 红色按钮的下标（翻译成破坏性的，其实就是那个红色的按钮）

NSInteger destructiveButtonIndex;

// 获取第一个其他按钮的下标(只读)

NSInteger firstOtherButtonIndex;

// UIActionSheet是否可见（只读）

BOOL visible;

// show a sheet animated. you can specify either a toolbar, a tab bar, a bar butto item or a plain view. We do a special animation if the sheet rises from // a toolbar, tab bar or bar button item and we will automatically select the correct style based on the bar style. if not from a bar, we use // UIActionSheetStyleDefault if automatic style set // 如果要将ActonSheet 与工具栏或者标签栏对齐，可以使用showFromToolBar(showFromTabBar)

- (void)showFromToolbar:(UIToolbar *)view;
- (void)showFromTabBar:(UITabBar *)view;

// showFromBarButtonItem，就是popover会指向个BarButtonItem。在iPhone上只能使用showInView，如果是universal app，要用些if来判断。用delegate来知道用户选择了什么

- (void)showFromBarButtonItem:(UIBarButtonItem *)item animated:(BOOL)animated;

// showFromRect，在ipad上指定个矩形区域，它会在其上显示个popover

- (void)showFromRect:(CGRect)rect inView:(UIView *)view animated:(BOOL)animated;

// 显示在iphone的中间位置，它会从下往上滑动；在ipad上它会放在中间，所以在ipad上从不用showInView

- (void)showInView:(UIView *)view;

// hides alert sheet or popup. use this method when you need to explicitly dismiss the alert. // it does not need to be called if the user presses on a button

- (void)dismissWithClickedButtonIndex:(NSInteger)buttonIndex animated:(BOOL)animated;

UIActionSheetDelegate协议（可选）

// 点击UIActionSheet会调用的函数，buttonIndex为所点击button在UIActionSheet的下标

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex;

// 点击取消按钮会调用的函数

- (void)actionSheetCancel:(UIActionSheet *)actionSheet;

// 将来显示ActionSheet

- (void)willPresentActionSheet:(UIActionSheet *)actionSheet;

// 显示ActionSheet

- (void)didPresentActionSheet:(UIActionSheet *)actionSheet;

// ActionSheet将要消失

- (void)actionSheet:(UIActionSheet *)actionSheet willDismissWithButtonIndex:(NSInteger)buttonIndex;

// ActionSheet消失

- (void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex;