枚举型typedef

一. 定义枚举型

//常用typedef NS_ENUM(NSInteger, UIButtonType) {    UIButtonTypeCustom = 0,              UIButtonTypeSystem NS_ENUM_AVAILABLE_IOS(7_0),      UIButtonTypeDetailDisclosure,    UIButtonTypeInfoLight,    UIButtonTypeInfoDark,    UIButtonTypeContactAdd};//ortypedef NS_OPTIONS(NSUInteger, UIControlState) {    UIControlStateNormal       = 0,    UIControlStateHighlighted  = 1 << 0,                      UIControlStateDisabled     = 1 << 1,    UIControlStateSelected     = 1 << 2,                      UIControlStateFocused NS_ENUM_AVAILABLE_IOS(9_0) = 1 << 3,     UIControlStateApplication  = 0x00FF0000,                  UIControlStateReserved     = 0xFF000000               };//两者区别?//NS_ENUM, 取值时只能取其中一个,单选题//NS_OPTIONS, 可以使用|(或运算符),多选题//我的使用经验://当你的枚举型定义在任意一个.h文件, 比如你封装的view类, 如果vc引入此.h文件,就能直接在vc中使用此枚举类型的.//在架构级别,可以写在专门的.h文件,并导入.pch文件中

二. 定义Block类型

typedef void(^MyBlock)(UIButtonType type, NSInteger index);//block的触发,必须先判断self.block是否不为nil;//正如delegate的方法触发,先判断self.delegte!=nil, 且responseTo方法.