工廠模式是比較簡單，也是比較好用的一種方式。根本上說，工廠模式的目的就根據不同的要求輸出不同的產品。比如說吧，有一個生產鞋子的工廠，它能生產皮鞋，也能生產膠鞋。如果用程式碼設計，應該怎麼做呢？

typedef struct _Shoe{    int type;    void (*print_shoe)(struct _Shoe*);}Shoe;

void print_leather_shoe(struct _Shoe* pShoe){    assert(NULL != pShoe);    printf("This is a leather show!\n"
 
);}void print_rubber_shoe(struct _Shoe* pShoe){    assert(NULL != pShoe);    printf("This is a rubber shoe!\n");}

#define LEATHER_TYPE 0x01#define RUBBER_TYPE  0x02Shoe* manufacture_new_shoe(int type){    assert(LEATHER_TYPE == type || RUBBER_TYPE == type);    Shoe* pShoe = (Shoe*)malloc
 
(sizeof(Shoe));    assert(NULL != pShoe);    memset(pShoe, 0, sizeof(Shoe));    if(LEATHER_TYPE == type)    {        pShoe->type == LEATHER_TYPE;        pShoe->print_shoe = print_leather_shoe;    }    else    {        pShoe->type == RUBBER_TYPE;        pShoe->print_shoe = print_rubber_shoe;    }    return
 
 pShoe;}