链式编程思想

# 1，链式编程思想：是将多个操作（多行代码）通过点号（.）链接在一起成为一句代码，使代码可读性提高。

2，链式编程特点：方法的返回值是block，block必须返回对象本身（返回block时，block所在的方法调用者对象）block的参数是需要操作的值。

经典：masonry 框架

代码实例：简易计算器

- (void)viewDidLoad {

    [super viewDidLoad];

int result = [CalculateManager zwg_makeCalculates:^(CalculateManager *make) {

        make.add(10).add(10);

        make.div(2);

        make.multi(10).minus(2);

    }];

}

CalculateManager.h 文件中

#import

@interfaceCalculateManager :NSObject

@property (nonatomic, assign) int result;

@property (nonatomic, copy) NSString *name;

- (CalculateManager*(^)(intnum))add;// 加

- (CalculateManager*(^)(intnum))minus;// 减

- (CalculateManager*(^)(intnum))multi;//乘

- (CalculateManager*(^)(intnum))div;//除

CalculateManager.m 文件中

#import "CalculateManager.h"

@implementationCalculateManager

- (CalculateManager *(^)(int))add {

    return ^CalculateManager *(int num) {

        self.result+= num;

        NSLog(@"add : %d",self.result);

        return self;

    };

}

- (CalculateManager*(^)(int))minus {

    return ^CalculateManager *(int num) {

        self.result-= num;

        NSLog(@"minus : %d",self.result);

        return self;

    };

}

- (CalculateManager*(^)(int))multi {

    return ^CalculateManager *(int num){

        self.result*= num;

        NSLog(@"multi : %d",self.result);

        return self;

    };

}

- (CalculateManager *(^)(int))div {

    return ^CalculateManager *(int num) {

        self.result/= num;

        NSLog(@"div : %d",self.result);

        return self;

    };

}

NSObject+Calculate.h 文件

#import

@class CalculateManager;

@interfaceNSObject (Calculate)

+ (int)zwg_makeCalculates:(void(^)(CalculateManager*make))block;

@end

NSObject+Calculate.m 文件

#import "NSObject+Calculate.h"

#import "CalculateManager.h"

@implementationNSObject (Calculate)

+ (int)zwg_makeCalculates:(void(^)(CalculateManager*make))block {

    CalculateManager *calculate = [[CalculateManager alloc] init];

    block(calculate);

    returncalculate.result;

}