Mall billing system based on Rule mode (C # source code)

From: http://blog.csdn.net/andylin02/archive/2008/11/14/3302034.aspx

1. Using system;
3. Namespace cashsystem
4. {
5. // Thread class
6. Class crunmain
7. {
8. Public static void showmessage ()
9. {
10. Console. writeline ("----------------- please input your choise :------------");
11. Console. writeline ("/T/t0. quite ");
12. Console. writeline ("/T/T1. pay cash noremally ");
13. Console. writeline ("/T/T2. Pya cash in 8 rebate ");
14. Console. writeline ("/T/T3. pay cash in after 300 return 100 ");
15. Console. writeline ("-------------------------------------------------------");
16. }
18. Public static int main ()
19. {
20. Ccashcontext objcont = new ccashcontext ();
21. Ccashsuper objcash = NULL;
23. While (true)
24. {
25. Int nchoice = 0;
26. Int ncount = 0;
27. Double dumoney = 0.0;
28. Double duprice = 0.0;
30. Showmessage ();
31. Nchoice = convert. toint32 (console. Readline ());
33. Switch (nchoice)
34. {
35. Case 0:
36. Console. writeline ("press any key to quit! ");
37. Console. Read ();
38. Return 0;
40. Case 1:
41. Objcash = new ccashnormal ();
42. Break;
44. Case 2:
45. Objcash = new ccashrebate (0.8 );
46. Break;
48. Case 3:
49. Objcash = new ccashreturn (300,100 );
50. Break;
52. Default:
53. Objcash = NULL;
54. Break;
55. }
57. If (null = objcash)
58. {
59. Console. writeline ("input error! ");
60. Continue;
61. }
63. // Set cash object
64. Objcont. setbehavior (objcash );
66. Console. writeline ("Please input price :");
67. Duprice = convert. todouble (console. Readline ());
69. Console. writeline ("Please input count :");
70. Ncount = convert. toint32 (console. Readline ());
72. Dumoney = duprice * ncount;
74. Console. writeline ("the properly money you shoshould pay is" + objcont. getresult (dumoney ));
75. }
76. }
77. };
79. // Billing policy context
80. Class ccashcontext
81. {
82. // Set the policy action. The parameter is the specific sub-class of cash charge (normal, discount or rebate)
83. Public void setbehavior (ccashsuper objcash)
84. {
85. This. m_objcash = objcash;
86. }
88. Public double getresult (double dumoney)
89. {
90. If (null = This. m_objcash)
91. {
92. Console. writeline ("null = m_objcash ");
93. Return 0;
94. }
96. Return this. m_objcash.acceptcash (dumoney );
97. }
99. Private ccashsuper m_objcash;
100. };
102. Abstract class ccashsuper
103. {
104. Public abstract double acceptcash (double dumoney );
105. };
107. Class ccashreturn: ccashsuper
108. {
109. Public ccashreturn (double ducondition, double dureturn)
110. {
111. This. m_ducondition = ducondition;
112. This. m_dureturn = dureturn;
113. }
115. Public override double acceptcash (double dumoney)
116. {
117. If (dumoney> This. m_ducondition)
118. {
119. Dumoney-= This. m_dureturn;
120. }
122. Return dumoney;
123. }
125. Private double m_ducondition = 0.0;
126. Private double m_dureturn = 0.0;
127. };
129. Class ccashnormal: ccashsuper
130. {
131. Public override double acceptcash (double dumoney)
132. {
133. Return dumoney;
134. }
136. };
138. Class ccashrebate: ccashsuper
139. {
140. Public ccashrebate (double durebate)
141. {
142. This. m_durebate = durebate;
143. }
145. Public override double acceptcash (double dumoney)
146. {
147. Return dumoney * This. m_durebate;
148. }
151. Private double m_durebate;
152. };
153. }