ASP without components to generate picture verification code with canvas

No Components | verification Code

Click here to download the source

The relevant pictures are as follows:

Dim Objcanvas
Dim Pointx,pointy,pointcolor
Dim itemp
Dim Safecode
Dim R,g,b,cc,kk

Const Camount = 36 ' text quantity
Const ccode = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
Cc=80
Kk=30
Safecode = ""
Session ("Safecode") = ""

bgcolor = "FFFFFF"

R = Mid (bgcolor,1,2)
G = Mid (bgcolor,3,2)
B = Mid (bgcolor,5,2)



R = Dechex (r)
g = Dechex (g)
b = Dechex (b)

Set Objcanvas = New Canvas

Objcanvas.globalcolourtable (0) = RGB (255,255,255) ' White
Objcanvas.globalcolourtable (1) = RGB (0,0,0) ' Black
Objcanvas.globalcolourtable (2) = RGB (255,0,0) ' Red
Objcanvas.globalcolourtable (3) = RGB (0,255,0) ' Green
Objcanvas.globalcolourtable (4) = RGB (0,0,255) ' Blue
Objcanvas.globalcolourtable (5) = RGB (128,0,0)
Objcanvas.globalcolourtable (6) = RGB (0,128,0)
Objcanvas.globalcolourtable (7) = RGB (0,0,128)
Objcanvas.globalcolourtable (8) = RGB (128,128,0)
Objcanvas.globalcolourtable (9) = RGB (0,128,128)
Objcanvas.globalcolourtable (+) = RGB (128,0,128)
Objcanvas.globalcolourtable (one) = RGB (r,g,b)

Objcanvas.backgroundcolourindex = 11

Objcanvas.resize Cc,kk,false


' Randomize timer
' Safecode = CInt (8999*rnd+1000)

    randomize
For i = 0 to 3
  safecode = Safecode & "" & Mid (Ccode, T (RND * camount) + 1, 1)
    next
' miscellaneous point
  
for itemp = 0 to
  ra Ndomize timer
  pointx = Int (Rnd * cc)
  pointy = Int (Rnd * kk)
  pointcolor = int (RND * 3) +2
  objcanvas.foregroundcolourindex = pointcolor  
  objcanvas.line Pointx,pointy,pointx,pointy
  
  next
' border
Objcanvas.foregroundcolourindex = 1
Objcanvas.line 1,1,cc,1
objcanvas.line 1,kk,1,1
objcanvas.line 1,kk,cc,kk
Objcanvas.line cc,1,cc,kk

Session ("Safecode") = Safecode
Dim sc,sk
' Text
Randomize timer
sc = CInt (3*rnd)
SK = CInt (3*rnd)
Objcanvas.drawtextwe sc,sk,safecode
objcanvas.write
  

Function Dechex (HSTR)

Dim result
Dim i,l

result = 0


L = Len (HSTR)

For i = L-1 to 0 Step-1

result = result + (^ i) *getdecbit (Mid (hstr,i+1,1))

Next

Dechex = result

End Function

Function Getdecbit (HSTR)

Dim result
Dim R (16)
Dim I

result = 0

R (0) = "0"
R (1) = "1"
R (2) = "2"
R (3) = "3"
R (4) = "4"
R (5) = "5"
R (6) = "6"
R (7) = "7"
R (8) = "8"
R (9) = "9"
R (Ten) = "A"
R (one) = "B"
R (a) = "C"
R (+) = "D"
R (d) = "E"
R (m) = "F"

For i = 0 to 15

If Hstr=r (i) Then result = I:exit for

Next

Getdecbit = result

End Function