Turn: more perfect common Verification Code Class

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2. Using system;
4. Using system. collections;
6. Using system. componentmodel;
8. Using system. Data;
10. Using system. drawing;
12. Using system. Web;
14. Using system. Web. sessionstate;
16. Using system. Web. UI;
18. Using system. Web. UI. webcontrols;
20. Using system. Web. UI. htmlcontrols;
22. Namespace webapplication1. Verification Code
24. {
26. /// <Summary>
28. /// Perfect Random verification code 0.10
30. /// Verion: 0.10
32. /// Description: The verification code is randomly generated and rotated to a certain angle. The font color is different.
34. /// </Summary>
36. Public class validatecode: system. Web. UI. Page
38. {
40. Private void page_load (Object sender, system. eventargs E)
42. {
44. String randomcode = This. createrandomcode (4 );
46. Session ["validatecode"] = randomcode;
48. // Viewstate ["validatecode"] = randomcode;
50. This. createimage (randomcode );
52. }
54. /// <Summary>
56. /// Generate random code
58. /// </Summary>
60. /// <Param name = "length"> Number of random codes </param>
62. /// <Returns> </returns>
64. Private string createrandomcode (INT length)
66. {
68. Int rand;
70. Char code;
72. String randomcode = string. empty;
74. // Generate a verification code of a certain length
76. System. Random random = new random ();
78. For (INT I = 0; I <length; I ++)
80. {
82. Rand = random. Next ();
84. If (RAND % 3 = 0)
86. {
88. Code = (char) ('A' + (char) (RAND % 26 ));
90. }
92. Else
94. {
96. Code = (char) ('0' + (char) (RAND % 10 ));
98. }
100. Randomcode + = code. tostring ();
102. }
104. Return randomcode;
106. }
108. /// <Summary>
110. /// Create a random Image
112. /// </Summary>
114. /// <Param name = "randomcode"> Random Code </param>
116. Private void createimage (string randomcode)
118. {
120. Int randangle = 45; // random Rotation Angle
122. Int mapwidth = (INT) (randomcode. length * 23 );
124. Bitmap map = new Bitmap (mapwidth, 28); // creates an image background.
126. Graphics graph = graphics. fromimage (MAP );
128. Graph. Clear (color. aliceblue); // clear the screen and fill in the background.
130. Graph. drawrectangle (new pen (color. Black, 0), 0, 0, map. Width-1, map. Height-1); // draw a border
132. // Graph. smoothingmode = system. Drawing. drawing2d. smoothingmode. antialias; // Mode
134. Random Rand = new random ();
136. // Generate background noise
138. Pen blackpen = new pen (color. lightgray, 0 );
140. For (INT I = 0; I <50; I ++)
142. {
144. Int x = Rand. Next (0, map. width );
146. Int y = Rand. Next (0, map. Height );
148. Graph. drawrectangle (blackpen, X, Y, 1, 1 );
150. }
152. // Rotate the verification code to prevent Machine recognition
154. Char [] chars = randomcode. tochararray (); // split the string into a single character array
156. // Text distance
158. Stringformat format = new stringformat (stringformatflags. noclip );
160. Format. Alignment = stringalignment. Center;
162. Format. linealignment = stringalignment. Center;
164. // Define the color
166. Color [] C = {color. Black, color. Red, color. darkblue, color. Green, color. Orange, color. Brown, color. darkcyan, color. Purple };
168. // Define the font
170. String [] font = {"verdana", "Microsoft sans serif", "Comic Sans MS", "Arial", ""};
172. For (INT I = 0; I <chars. length; I ++)
174. {
176. Int cIndex = Rand. Next (7 );
178. Int findex = Rand. Next (5 );
180. Font F = new system. Drawing. Font (font [findex], 13, system. Drawing. fontstyle. Bold); // font style (parameter 2 indicates the font size)
182. Brush B = new system. Drawing. solidbrush (C [cIndex]);
184. Point dot = new point (16, 16 );
186. // Graph. drawstring (Dot. X. tostring (), fontstyle, new solidbrush (color. Black), 10,150); // test the display spacing of X coordinates.
188. Float angle = Rand. Next (-randangle, randangle); // degrees of Rotation
190. Graph. translatetransform (Dot. X, Dot. Y); // move the cursor to the specified position
192. Graph. rotatetransform (angle );
194. Graph. drawstring (chars [I]. tostring (), F, B, 1, 1, format );
196. // Graph. drawstring (chars [I]. tostring (), fontstyle, new solidbrush (color. Blue), 1, 1, format );
198. Graph. rotatetransform (-angle); // go back
200. Graph. translatetransform (2,-dot. Y); // move the cursor to the specified position
202. }
204. // Graph. drawstring (randomcode, fontstyle, new solidbrush (color. Blue), 2, 2); // standard random code
206. // Generate an image
208. System. Io. memorystream MS = new system. Io. memorystream ();
210. Map. Save (MS, system. Drawing. imaging. imageformat. GIF );
212. Response. clearcontent ();
214. Response. contenttype = "image/GIF ";
216. Response. binarywrite (Ms. toarray ());
218. Graph. Dispose ();
220. Map. Dispose ();
222. }
224. # Generated by region web Form DesignerCode
226. Override protected void oninit (eventargs E)
228. {
230. //
232. // Codegen: This call is required by the ASP. NET web form designer.
234. //
236. Initializecomponent ();
238. Base. oninit (E );
240. }
242. /// <Summary>
244. /// The designer supports the required methods-do not use the code editor to modify
246. /// Content of this method.
248. /// </Summary>
250. Private void initializecomponent ()
252. {
254. This. Load + = new system. eventhandler (this. page_load );
256. }
258. # Endregion
260. }
262. }