建造者模式 (Builder Pattern)

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于 2025-08-06 08:40:10 发布 · 224 阅读

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#建造者模式 #c++

🏗️ 建造者模式 (Builder Pattern)

📖 模式简介

建造者模式是一种创建型设计模式，它允许你分步骤创建复杂对象。该模式允许你使用相同的创建代码生成不同类型和形式的对象。建造者模式将复杂对象的构建过程抽象出来，使得同样的构建过程可以创建不同的表示。

🔍 问题场景

想象你正在开发一个游戏，需要创建各种类型的角色。每个角色都有很多属性：

基础属性：姓名、职业、等级、生命值、魔法值
装备属性：武器、护甲、饰品
技能属性：主动技能、被动技能
外观属性：头发颜色、眼睛颜色、皮肤颜色等

❌ 没有使用设计模式的实现

#include <iostream>
#include <string>
#include <vector>

// 糟糕的实现方式
class GameCharacter {
   
   
private:
    std::string name;
    std::string profession;
    int level;
    int health;
    int mana;
    std::string weapon;
    std::string armor;
    std::string accessory;
    std::vector<std::string> activeSkills;
    std::vector<std::string> passiveSkills;
    std::string hairColor;
    std::string eyeColor;
    std::string skinColor;
    bool hasMount;
    std::string mountType;
    bool hasPet;
    std::string petType;
    
public:
    // 噩梦般的构造函数
    GameCharacter(const std::string& name, const std::string& profession, 
                  int level, int health, int mana, const std::string& weapon,
                  const std::string& armor, const std::string& accessory,
                  const std::vector<std::string>& activeSkills,
                  const std::vector<std::string>& passiveSkills,
                  const std::string& hairColor, const std::string& eyeColor,
                  const std::string& skinColor, bool hasMount = false,
                  const std::string& mountType = "", bool hasPet = false,
                  const std::string& petType = "")
        : name(name), profession(profession), level(level), health(health),
          mana(mana), weapon(weapon), armor(armor), accessory(accessory),
          activeSkills(activeSkills), passiveSkills(passiveSkills),
          hairColor(hairColor), eyeColor(eyeColor), skinColor(skinColor),
          hasMount(hasMount), mountType(mountType), hasPet(hasPet), petType(petType) {
   
   }
    
    void display() const {
   
   
        std::cout << "Character: " << name << " (" << profession << ")" << std::endl;
        std::cout << "Level: " << level << ", HP: " << health << ", MP: " << mana << std::endl;
        std::cout << "Equipment: " << weapon << ", " << armor << ", " << accessory << std::endl;
        // ... 更多输出
    }
};

// 使用示例 - 参数地狱
void badExample() {
   
   
    std::vector<std::string> skills1 = {
   
   "Fireball", "Lightning"};
    std::vector<std::string> passives1 = {
   
   "Magic Mastery"};
    
    // 17个参数！这还不包括可能的扩展
    GameCharacter mage("Gandalf", "Wizard", 50, 800, 1200, "Magic Staff",
                       "Robe of Power", "Ring of Wisdom", skills1, passives1,
                       "White", "Blue", "Pale", true, "Unicorn", false, "");
    
    std::vector<std::string> skills2 = {
   
   "Slash", "Shield Bash"};
    std::vector<std::string> passives2 = {
   
   "Heavy Armor Mastery", "Weapon Expert"};
    
    GameCharacter warrior("Conan", "Warrior", 45, 1500, 300, "Great Sword",
                          "Plate Mail", "Strength Amulet", skills2, passives2,
                          "Black", "Brown", "Tanned", true, "War Horse", true, "Wolf");
}