Block声明的几种写法

#import <Foundation/Foundation.h>

typedef void(^BlockB)(int b);
typedef void(^BlockD)(int d);

@interface BlockWriting : NSObject

@property (nonatomic, copy) void(^BlockA)(int a);

@property (nonatomic, copy) BlockB blockB;

- (void)doBlockC:(void(^)(int c))blockC;

- (void)doBlockD:(BlockD)blockD;

@end

参考链接:
关于Block的定义,和作为参数的写法
iOS开发－Object-C Block的实现方式
Objective C中Block的几种常用写法