设计模式之抽象工厂模式（C语言）

介绍：

​ 抽象工厂模式是一种创建型设计模式；

作用：

​ 提供统一的接口让用户根据不同的需求创建出不同的工厂；

类比：

​ 一个制造家具的工厂，可以根据用户不同的诉求，制造出不同风格的家具；

代码示例：

首先定义出不同类型的家具以供生产：

void modern_chair(void)
{
	printf("A modern chairrn");
}

void modern_dest(void)
{
    printf("A modern deskrn");
}

void victorian_chair(void)
{
    printf("A victorian chairrn");
}

void victorian_dest(void)
{
    printf("A victorian deskrn");
}

其次定义出工厂要制作的家具：

typedef struct
{
    void (*chair)(void);
}Chair_t;
 
typedef struct
{
    void (*desk)(void);
}Desk_t;

设计出工厂的具体生产内容：

Chair_t* make_modern_chair(void)
{
    Chair_t* pChair = (Chair_t)malloc(sizeof(Chair_t));
    assert(pChair != NULL);
    pChair->chair = modern_chair;
    return pChair;
}

Chair_t* make_victorian_chair(void)
{
    Chair_t* pChair = (Chair_t)malloc(sizeof(Chair_t));
    assert(pChair != NULL);
    pChair->chair = victorian_chair;
    return pChair;
}

Desk_t* make_modern_desk(void)
{
    Desk_t* pDesk = (Dest_t)malloc(sizeof(Dest_t));
    assert(pDesk != NULL);
    pDesk->desk = modern_desk;
    return pDesk;
}

Desk_t* make_victorian_desk(void)
{
    Desk_t* pDesk = (Dest_t)malloc(sizeof(Dest_t));
    assert(pDesk != NULL);
    pDesk->desk = victorian_desk;
    return pDesk;
}

接下来将工厂定义出来：

typedef struct
{
	Chair_t (*make_chair)(void);
    Dest_t (*make_desk)(void);
}Furniture_factory;

创建工厂：

Furniture_factory* Creat_furniture_factory(char* type)
{
	Furniture_factory* pFurniture_factory = (Furniture_factory*)malloc(sizeof(Furniture_factory));
    assert(pFurniture_factory != NULL)
    if(memcmp(type, "modern") == 0)
    {
        pFurniture_factory->make_chair = make_modern_chair;
        pFurniture_factory->make_desk = make_modern_desk;
    }
    else if(memcmp(type, "victorian") == 0)
    {
        pFurniture_factory->make_chair = make_victorian_chair;
        pFurniture_factory->make_desk = make_victorian_desk;
    }
    else
    {
        printf("type is invalidrn");
    }
}