The xbm graph generated by ASP can be used as a verification code.

This program is mainly to generate a random number, and then convert the generated random number as the content of the xbm image, and finally display the image. the number to be obtained during verification is compared with the session ("validatecode"). If they are equal, the verification is passed (note that the two data types in comparison are consistent ).

How to display the generated image? </img>

For the format information of the xbm image, see here
Http://www.zdnet.com.cn/developer/tech/story/0,2000081602,39134972,00.htm

The xbm. ASP code is as follows:

Program code:

<! -- # Include file = "numcode. asp" --> <% 'Enable Buffering Response. Buffer = true With response . Expires =-1 . Addheader "Pragma", "No-Cache" . Addheader "cache-ctrol", "No-Cache" End Dim num Randomize Num = int (7999 * RND + 2000) Session ("validatecode") = num Dim image Dim width, height Dim Digtal Dim Length Dim sort Dim HC Length = 4 Hc = CHR (13) & CHR (10) Redim sort (length) Digital = "" For I = 1 to length-len (Num) Digital = digital & "0" Next For I = 1 to Len (Num) Digital = digital & Mid (Num, I, 1) Next For I = 1 to Len (digital) Sort (I) = mid (digital, I, 1) Next Width = 8 * Len (digital) Height = 10 Response. contenttype = "image/X-xbitmap" Image = "# define counter_width" & width & HC Image = Image & "# define counter_height" & Height & HC Image = Image & "static unsigned char counter_bits [] = {" & HC For I = 1 to height For j = 1 to length Image = Image & A (sort (J), I )&"," Next Next Image = left (image, Len (image)-1) Image = Image & "};" & HC Response. Write Image %>

The numcode. ASP code is as follows:

Program code:

<% Dim A (10, 10) A (0, 1) = "0x3c" 'number 0 A (0, 2) = "0x66" A (0, 3) = "0xc3" A (0, 4) = "0xc3" A (0, 5) = "0xc3" A (0, 6) = "0xc3" A (0, 7) = "0xc3" A (0, 8) = "0xc3" A (0, 9) = "0x66" A (0, 10) = "0x3c" A (1, 1) = "0x18" 'Number 1 A (1, 2) = "0x1c" A (1, 3) = "0x18" A (1, 4) = "0x18" A (1, 5) = "0x18" A (1, 6) = "0x18" A (1, 7) = "0x18" A (1, 8) = "0x18" A (1, 9) = "0x18" A (0, 10) = "0x7e" A (2, 1) = "0x3c" 'number 2 A (2, 2) = "0x66" A (2, 3) = "0x60" A (2, 4) = "0x60" A (2, 5) = "0x30" A (2, 6) = "0x18" A (2, 7) = "0x0c" A (2, 8) = "0x06" A (2,9) = "0x06" A (2, 10) = "0x7e" A (3, 1) = "0x3c" 'number 3 A (3, 2) = "0x66" A (3, 3) = "0xc0" A (3, 4) = "0x60" A (3, 5) = "0x1c" A (3, 6) = "0x60" A (3, 7) = "0xc0" A (3, 8) = "0xc0" A (3,9) = "0x66" A (3,10) = "0x38" A (4, 1) = "0x38" 'Number 4 A (4, 2) = "0x3c" A (4, 3) = "0x36" A (4, 4) = "0x33" A (4, 5) = "0x33" A (4, 6) = "0x33" A (4, 7) = "0xff" A (4,8) = "0x30" A (4,9) = "0x30" A (4,10) = "0xfe" A (5, 1) = "0xfe" 'number 5 A (5, 2) = "0xfe" A (5, 3) = "0x06" A (5, 4) = "0x06" A (5, 5) = "0x3e" A (5, 6) = "0x60" A (5, 7) = "0xc0" A (5, 8) = "0xc3" A (5, 9) = "0x66" A (5, 10) = "0x3c" A (6, 1) = "0x60" 'Number 6 A (6, 2) = "0x30" A (6, 3) = "0x18" A (6, 4) = "0x0c" A (6, 5) = "0x3e" A (6, 6) = "0x63" A (6, 7) = "0xc3" A (6, 8) = "0xc3" A (6, 9) = "0x66" A (6, 10) = "0x3c" A (7,1) = "0xff" 'number 7 A (7,2) = "0xc0" A (7,3) = "0x60" A (7,4) = "0x30" A (7,5) = "0x18" A (7, 6) = "0x18" A (7, 7) = "0x18" A (7,8) = "0x18" A (7,9) = "0x18" A (7,10) = "0x18" A (8, 1) = "0x3c" 'number 8 A (8, 2) = "0x66" A (8, 3) = "0xc3" A (8, 4) = "0x66" A (8, 5) = "0x3c" A (8, 6) = "0x66" A (8, 7) = "0xc3" A (8, 8) = "0xc3" A (8, 9) = "0x66" A (8, 10) = "0x3c" A (9,1) = "0x3c" 'Number 9 A (9, 2) = "0x66" A (9,3) = "0xc3" A (9,4) = "0xc3" A (9,5) = "0x66" A (9,6) = "0x3c" A (9, 7) = "0x18" A (9,8) = "0x0c" A (9,9) = "0x06" A (9,10) = "0x03" %>