谈到链式编程,那Masonry几乎就是最经典的代表.如:
make.top.equalTo(self.view).offset()
像这样top.equalTo(self.view).offset(60)通过”点”语法，将需要执行的代码块连续的书写下去,就是链式编程.它能使代码简单易读，书写方便
1.传统写法,两个方法需要单独调用,也不能任意组合顺序
创建Person类
Person.h: - (void)eat1;
- (void)sleep1;
Person.m: - (void)eat1
{
NSLog(@"%s",__FUNCTION__);
}
- (void)sleep1
{
NSLog(@"%s",__FUNCTION__);
}
控制器中调用Person类中方法
ViewController.m: Person *person = [[Person alloc] init];
[person eat1];
[person sleep1];
2.用’[]’实现连续调用
Person.h: - (Person *)eat2;
- (Person *)sleep2;
Person.m: - (Person *)eat2
{
NSLog(@"%s",__FUNCTION__);
return self;
}
- (Person *)sleep2
{
NSLog(@"%s",__FUNCTION__);
return self;
}
ViewController.m: [[person eat2] sleep2];
[[person sleep2] eat2];
3.用block实现链式
//person.eat3相当于get方法(很妙的自己可以试一下)
Person.h: - (void (^)())eat3;
- (void (^)())sleep3;
Person.m: - (void (^)())eat3
{
//定义block
void (^eat3Block)() = ^ {
NSLog(@"%s",__FUNCTION__);
};
return eatBlock;
}
- (void (^)())sleep3
{
return ^ {
NSLog(@"%s",__FUNCTION__);
};;
}
ViewController.m: person.eat3();
person.sleep3();
4.实现 链式(无参)
Person.h: - (Person * (^)())eat4;
- (Person * (^)())sleep4;
Person.m: - (Person *(^)())eat4
{
Person * (^eat4Block)() = ^ {
NSLog(@"%s",__FUNCTION__);
return self;
};
return eat4Block;
}
//上下两种写法一样
- (Person *(^)())sleep4
{
return ^ {
NSLog(@"%s",__FUNCTION__);
return self;
};
}
ViewController.m: person.eat4().sleep4();
person.sleep4().eat4();
5.实现 链式(带参)
//person.eat3相当于get方法(很妙的自己可以试一下) 返回值是block 调用block需要传参数 int 调用block返回值是对象本身
Person.h: - (Person * (^)(NSString *foodName))eat5;
- (Person * (^)(NSInteger hour))sleep5;
Person.m: - (Person *(^)(NSString *))eat5
{
Person * (^eat5Block)() = ^(NSString *foodName) {
NSLog(@"吃: %@",foodName);
return self;
};
return eat5Block;
}
//上下两种写法一样
- (Person *(^)(NSInteger))sleep5
{
return ^(NSInteger hour) {
NSLog(@"睡了%ld小时",(long)hour);
return self;
};
}
ViewController.m: person.eat5(@"蛋糕").sleep5();
person.sleep5().eat5(@"面包");