c++设计模式之建造者模式

建造者模式:
结构:
1.产品对象:一类产品的抽象，具体产品的建造应该在具体建造者中实现
3.抽象建造者
4.具体建造者：对于每种具体产品都应该有一个对应的建造者，其中应该有一个抽象产品对象成员变量
5.装配者：建造者对各个零件单独建造，没有顺序，因此，需要早装配者中确定建造顺序

优点:
1.建造者独立，易扩展
缺点:
1.产品必须具有相同属性
2.产品越多，需要的建造者类也就越多

场景:
手机有很多，小米，华为，三星，苹果，虽然名称不一样，但是内部结构基本差不多。这种场景就很适合使用建造者模式:

  1 //IBuilder.h
  2 #pragma once
  3 #include "Phone.h"
  4 class IBuilder
  5 {
  6 public:
  7     IBuilder();
  8     ~IBuilder();
  9 protected:
 10     Phone* phone_;
 11 public:
 12     virtual void build_camera() = 0;
 13     virtual void build_earphone() = 0;
 14     virtual void build_screen() = 0;
 15     virtual Phone* get_phone();
 16 };
 17 
 18 class XiaomiBuilder:public IBuilder
 19 {
 20 public:
 21     XiaomiBuilder();
 22     void build_camera();
 23     void build_earphone();
 24     void build_screen();
 25 };
 26 
 27 
 28 class HuaweiBuilder :public IBuilder
 29 {
 30 public:
 31     HuaweiBuilder();
 32     void build_camera();
 33     void build_earphone();
 34     void build_screen();
 35 };
 36 
 37 //IBuilder.cpp
 38 #include "pch.h"
 39 #include "IBuilder.h"
 40 
 41 
 42 IBuilder::IBuilder()
 43 {
 44 }
 45 
 46 
 47 IBuilder::~IBuilder()
 48 {
 49 }
 50 
 51 Phone* IBuilder::get_phone() 
 52 {
 53     return phone_;
 54 }
 55 
 56 XiaomiBuilder::XiaomiBuilder() 
 57 {
 58     phone_ = new Phone;
 59 }
 60 
 61 void XiaomiBuilder::build_camera() 
 62 {
 63     phone_->set_camera("xiaomi camera!!1");
 64 }
 65 
 66 void XiaomiBuilder::build_screen() 
 67 {
 68     phone_->set_screen("xiaomi screen!!!");
 69 }
 70 
 71 void XiaomiBuilder::build_earphone() 
 72 {
 73     phone_->set_earphone("xiaomi earphone!!!");
 74 }
 75 
 76 HuaweiBuilder::HuaweiBuilder()
 77 {
 78     phone_ = new Phone;
 79 }
 80 
 81 void HuaweiBuilder::build_camera()
 82 {
 83     phone_->set_camera("huawei camera!!1");
 84 }
 85 
 86 void HuaweiBuilder::build_screen()
 87 {
 88     phone_->set_screen("huawei screen!!!");
 89 }
 90 
 91 void HuaweiBuilder::build_earphone()
 92 {
 93     phone_->set_earphone("huawei earphone!!!");
 94 }
 95 
 96 //Assembler.h
 97 #pragma once
 98 #include "IBuilder.h"
 99 class Assembler
100 {
101 public:
102     Assembler();
103     ~Assembler();
104     void create(IBuilder* builedr);
105 };
106 
107 //Assembler.cpp
108 #include "pch.h"
109 #include "Assembler.h"
110 
111 
112 Assembler::Assembler()
113 {
114 }
115 
116 
117 Assembler::~Assembler()
118 {
119 }
120 
121 
122 void Assembler::create(IBuilder* builedr) 
123 {
124     builedr->build_screen();
125     builedr->build_earphone();
126     builedr->build_camera();
127 }
128 
129 //Phone.h
130 #pragma once
131 #include <iostream>
132 #include <string.h>
133 using namespace std;
134 
135 class Phone
136 {
137 public:
138     Phone();
139     ~Phone();
140     void set_camera(string camera);
141     void set_screen(string screen);
142     void set_earphone(string earphone);
143     void display_camera();
144     void display_earphone();
145     void display_screen();
146 private:
147     string camera_;
148     string screen_;
149     string earphone_;
150 };
151 
152 //Phone.cpp
153 #include "pch.h"
154 #include "Phone.h"
155 
156 
157 Phone::Phone()
158 {
159 }
160 
161 
162 Phone::~Phone()
163 {
164 }
165 
166 void Phone::set_camera(string camera) 
167 {
168     camera_ = camera;
169 }
170 
171 void Phone::set_earphone(string earphone) 
172 {
173     earphone_ = earphone;
174 }
175 
176 void Phone::set_screen(string screen) 
177 {
178     screen_ = screen;
179 }
180 
181 void Phone::display_camera() 
182 {
183     cout << camera_.c_str() << endl;
184 }
185 
186 void Phone::display_earphone() 
187 {
188     cout << earphone_.c_str() << endl;
189 }
190 
191 void Phone::display_screen() 
192 {
193     cout << screen_.c_str() << endl;
194 }
195 
196 //main.cpp
197 #include "Phone.h"
198 #include "IBuilder.h"
199 using namespace std;
200 
201 #ifndef SAFE_DELETE
202 #define  SAFE_DELETE(p){if(p){delete (p);(p)=NULL;}}
203 #endif
204 
205 
206 int main()
207 { 
208     IBuilder* xiaomi = new XiaomiBuilder;
209     IBuilder* huawei = new HuaweiBuilder;
210     Assembler* assembler = new Assembler;
211     assembler->create(xiaomi);
212     assembler->create(huawei);
213 
214     Phone* xiaomi_phone = xiaomi->get_phone();
215     Phone* huawei_phone = huawei->get_phone();
216 
217     xiaomi_phone->display_camera();
218     xiaomi_phone->display_earphone();
219     xiaomi_phone->display_screen();
220 
221     huawei_phone->display_camera();
222     huawei_phone->display_earphone();
223     huawei_phone->display_screen();
224 
225 
226     SAFE_DELETE(xiaomi);
227     SAFE_DELETE(xiaomi_phone);
228     SAFE_DELETE(huawei);
229     SAFE_DELETE(huawei_phone);
230     SAFE_DELETE(assembler);
231 
232     getchar();
233 }

//运行结果