链式语法—学习

#import "ViewController.h"#import "Person.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.        Person *p=[[Person alloc]init];    //实现链式语法，主要包含 点语法、小括号调用、连续访问 三部分    // 点语法在编译时，p.who 会被替换成 [p who]，返回一个block    //1. p.who -> 获得一个 Block；    //2. Block实现 并返回了 P,     p = p.who(@"我是谁")    //3. p.调用后边的方法    p.who(@"我是谁").where(@"我在哪").doSomething(@"我在干啥？");       }

#import <Foundation/Foundation.h>@interface Person : NSObject//声明方法名为: xxx，该方法的返回值类型为一个 Block，而此 Block 的返回值设为类本身。-(Person * (^)(NSString *who))who;-(Person * (^)(NSString *where))where;-(Person * (^)(NSString *thing))doSomething;@end

#import "Person.h"@implementation Person-(Person * (^)(NSString *who))who{    return ^(NSString *who){        NSLog(@"%@",who);        return self;    };}-(Person * (^)(NSString *where))where{    return ^(NSString *where){        NSLog(@"%@",where);        return self;    };    }-(Person * (^)(NSString *thing))doSomething{    return ^(NSString *thing){        NSLog(@"%@",thing);        return self;    };    }@end