Design Pattern-Observer pattern (terrorist attack, Earthquake Example, class Relation Diagram)

1. Using system;
2. Using system. Collections. Generic;
3. Using system. text;
5. Namespace consoleapplication1
6. {
7. Internal interface warning
8. {
9. String situation
10. {
11. Get;
12. Set;
13. }
15. Void warn ();
17. Void add (peopleinschool P );
19. Void sub (peopleinschool P );
20. }
22. Class initialization estation: Warning
23. {
24. Private ilist <peopleinschool> Field = new list <peopleinschool> ();
25. String situation;
26. Public String situation
27. {
28. Get
29. {
30. Return situation;
31. }
32. Set
33. {
34. Situation = value;
35. }
36. }
38. Public void warn ()
39. {
40. Foreach (peopleinschool P in field)
41. {
42. P. warningreceived ();
43. }
44. }
46. Public void add (peopleinschool P)
47. {
48. Field. Add (P );
49. }
51. Public void sub (peopleinschool P)
52. {
53. Field. Remove (P );
54. }
55. }
57. Class earthquakedepartment: Warning
58. {
60. String situation;
62. Private ilist <peopleinschool> Field = new list <peopleinschool> ();
64. Public String situation
65. {
66. Get
67. {
68. Return situation;
69. }
70. Set
71. {
72. Situation = value;
73. }
74. }
76. Public void warn ()
77. {
78. Foreach (peopleinschool P in field)
79. {
80. P. warningreceived ();
81. }
82. }
84. Public void add (peopleinschool P)
85. {
86. Field. Add (P );
87. }
89. Public void sub (peopleinschool P)
90. {
91. Field. Remove (P );
92. }
93. }
95. Abstract class peopleinschool
96. {
98. Protected warning field;
100. Public peopleinschool (warning W)
101. {
102. Field = W;
103. }
105. Public abstract void warningreceived ();
108. }
110. Class Teacher: peopleinschool
111. {
112. Public Teacher (warning W)
113. : Base (W)
114. {
116. }
118. Public override void warningreceived ()
119. {
120. Console. writeline ("I am a teacher" + field. Situation );
121. }
122. }
124. Class student: peopleinschool
125. {
126. Public student (warning W)
127. : Base (W)
128. {
130. }
132. Public override void warningreceived ()
133. {
134. Console. writeline ("I am a student" + field. Situation );
135. }
136. }
138. Class Client
139. {
140. Public static void main ()
141. {
142. Restore estation P = new restore estation ();
143. Teacher T = new teacher (P );
144. Student s = new student (P );
145. P. Add (t );
146. P. Add (s );
147. P. Situation = "terrorist attack !!! ";
148. P. Warn ();
149. P. Situation = "Pay attention to fire prevention and theft !!! ";
150. P. Warn ();
152. Earthquakedepartment E = new earthquakedepartment ();
153. T = new teacher (E );
154. S = new student (E );
155. E. Add (t );
156. E. Add (s );
157. E. Situation = "an earthquake is coming !!! ";
158. E. Warn ();
160. Console. Read ();
161. }
163. }
164. }