來自于《大話設(shè)計(jì)模式》
模板方法模式：定義一個(gè)操作中的算法的骨架，而將一些步驟延遲到子類中。模板方法使得子類可以不改變一個(gè)算法的結(jié)構(gòu)即可重定義該算法的某些特定步驟。
盡量將公共操作上移到基類中，這樣便于修改，代碼復(fù)用性更強(qiáng)。
UML 類圖：
代碼實(shí)現(xiàn) C++：
1 #include <iostream>
2 #include <string>
3 using namespace std;
4
5 class TestPaper
6 {
7 public:
8 virtual void TestQuestion1()
9 {
10 cout << "TestQuestion1" << endl;
11 cout << "Answer: " << Answer1() << endl;
12 }
13 virtual void TestQuestion2()
14 {
15 cout << "TestQuestion2" << endl;
16 cout << "Answer: " << Answer2() << endl;
17 }
18 virtual void TestQuestion3()
19 {
20 cout << "TestQuestion3" << endl;
21 cout << "answer: " << Answer3() << endl;
22 }
23 virtual const string Answer1() = 0
24 {
25 return "";
26 }
27 virtual const string Answer2() = 0
28 {
29 return "";
30 }
31 virtual const string Answer3() = 0
32 {
33 return "";
34 }
35 };
36
37 class TestPaperA : public TestPaper
38 {
39 public:
40 virtual const string Answer1()
41 {
42 return "a";
43 }
44 virtual const string Answer2()
45 {
46 return "b";
47 }
48 virtual const string Answer3()
49 {
50 return "c";
51 }
52 };
53
54 class TestPaperB : public TestPaper
55 {
56 public:
57 virtual const string Answer1()
58 {
59 return "c";
60 }
61 virtual const string Answer2()
62 {
63 return "b";
64 }
65 virtual const string Answer3()
66 {
67 return "a";
68 }
69 };
70
71 int main()
72 {
73 TestPaperA a;
74 a.TestQuestion1();
75 a.TestQuestion2();
76 a.TestQuestion3();
77
78 TestPaperB b;
79 b.TestQuestion1();
80 b.TestQuestion2();
81 b.TestQuestion3();
82
83 TestPaper* p;
84 p = new TestPaperA;
85 p->TestQuestion1();
86 p->TestQuestion2();
87 p->TestQuestion3();
88 delete p;
89
90 p = new TestPaperB;
91 p->TestQuestion1();
92 p->TestQuestion2();
93 p->TestQuestion3();
94 delete p;
95
96 return 0;
97 }
posted on 2011-04-25 16:41
unixfy 閱讀(177)
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