设计模式之原型模式（C语言）

设计模式之原型模式（C语言）

介绍：

​ 原型模式是一种创建型设计模式，使你可以通过复制原型来创建一个一模一样的新的对象，无需考虑创建过程，数据类型等内容；

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作用：

• 创建一个与原型一模一样的对象；

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解决问题：

• 即使原型的状态有所改变，也可以创建出与其当前状态一致的对象
• 省去了创建对象的复杂 *** 作，不必关注创建对象的具体过程

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类比：

​ 老师打印试卷，拿着原版试卷，可以复制出任意数量的试卷，原版试卷既为原型；

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代码示例：

#include 
#include 
#include 

#define VAR(name, id)   name##id

typedef struct Paper
{
    char* teacher_name;
    int class;
    char* question;
    struct Paper* (*copy)(struct Paper* pPaper);
} paper_t;



paper_t* paper_copy(paper_t* pPaper)
{
    paper_t* copy = (paper_t*)malloc(sizeof(paper_t));
    memcpy(copy, pPaper, sizeof(paper_t));
    return copy;
}


paper_t* clone(paper_t* pPaper)
{
    return pPaper->copy(pPaper);
}

void main(void)
{
    
	paper_t origin_paper = {"Li", 5, "1 + 1 = ?", paper_copy};
    
    
    for(int i = 1; i <= 10; i++)
    {
        paper_t* VAR(paper, i) = clone(&origin_paper);
        printf("paper_%d => name: %s, class: %d, question: %srn",
                i, VAR(paper, i)->teacher_name, VAR(paper, i)->class, VAR(paper, i)->question);
    }
}

输出：

paper_1 => name: Li, class: 5, question: 1 + 1 = ?
paper_2 => name: Li, class: 5, question: 1 + 1 = ?
paper_3 => name: Li, class: 5, question: 1 + 1 = ?
paper_4 => name: Li, class: 5, question: 1 + 1 = ?
paper_5 => name: Li, class: 5, question: 1 + 1 = ?
paper_6 => name: Li, class: 5, question: 1 + 1 = ?
paper_7 => name: Li, class: 5, question: 1 + 1 = ?
paper_8 => name: Li, class: 5, question: 1 + 1 = ?
paper_9 => name: Li, class: 5, question: 1 + 1 = ?
paper_10 => name: Li, class: 5, question: 1 + 1 = ?