OC block 常见几种用法

1.属性用法

^ 后面就是block的名称，必须是copy

#import <UIKit/UIKit.h>
#import <SCCUserInterface/SCCTableViewCellProtocol.h>
#import "CNNOrderButtonView.h"

@interface CNNCarOrderCell : UITableViewCell <SCCTableViewCellProtocol>

+ (CGFloat)cellHeightWithItem:(id)item width:(CGFloat)width;

@property (nonatomic, copy) void (^buttonTappedBlock)(NSInteger index, CNNOrderButtonActionType type);

@end

2.类外面申明，成为一种数据类型

(^CNNCloseLocationBlock) CNNCloseLocationBlock成为新的数据类型，即函数指针

#import <Foundation/Foundation.h>
typedef void (^CNNCloseLocationBlock)(NSDictionary *dict);

@interface CNNCloseCarLocationManager : NSObject
    
@property (nonatomic,copy) CNNCloseLocationBlock locationBlock;
    
@property (nonatomic,copy) void(^location)(NSError *error,NSDictionary*geolocation);
    
+ (instancetype)manager NS_SWIFT_NAME(sharedInstance());
    
- (void)startUpdatingLocation;
    
- (void)setGetLocationBlock:(void(^)(NSDictionary * dic))block;

- (void)setGetGeoLocationBlock:(void(^)(NSError *error,NSDictionary*geolocation))block;
@end

3.方法中的参数block用法

(^block xx) block名称从括号中写在外面成为参数

- (void)setGetLocationBlock:(void(^)(NSDictionary * dic))block;

总结: 一般情况(^)后面都会跟block名称，参数除外