图片验证码代码-asp验证码代码

图片验证码代码-asp教程验证码代码
<%@CodePage="65001"%>
<script language="vbscript" runat="server">
Option Explicit '显示声明
Dim showErrorImg
showErrorImg = False

function ChkPost()
  dim server_v1,server_v2
  chkpost=false
  server_v1=Cstr(Request.ServerVariables("HTTP_REFERER"))
  server_v2=Cstr(Request.ServerVariables("SERVER_NAME"))
  If Mid(server_v1,8,Len(server_v2))<>server_v2 then
   chkpost=False
  else
   chkpost=True
  end If
end Function

If Not ChkPost() Then
  showErrorImg = true
End If

    '''''''''''''''''''''''''''''''''''''''''''''
    ' Author: Layen .net教程">support@ssaw.net 84815733(QQ)
    ' Thanks: Laomi, Laomiao, NetRube
    '                                2006-01-02
    ' URL:    http://www.zzzyk.com/
    '''''''''''''''''''''''''''''''''''''''''''''

Class Com_GifCode_Class
  Public Noisy, Count, Width, Height, Angle, Offset, Border
  Private Graph(), Margin(3)
  Private Sub Class_Initialize()
   Randomize
   Noisy = 3 ' 干扰点出现的概率
   Count = 4 ' 字符数量
   Width = 40 ' 图片宽度
   Height = 20 ' 图片高度
   Angle = 2 ' 角度随机变化量
   Offset = 6 ' 偏移随机变化量
   Border = 1.5 ' 边框大小
  End Sub

  Public Function Create2(str)
   Dim i
   Dim vIndex
   ReDim Graph(Width-1, Height-1)
   For i = 0 To Count - 1
    vIndex=CInt(Mid(str,i+1,1)-1)
    SetDraw vIndex, i
   Next
  End Function

  Sub SetDot(pX, pY)
   If pX * (Width-pX-1) >= 0 And pY * (Height-pY-1) >= 0 Then
    Graph(pX, pY) = 1
   End If
  End Sub

  Public Sub SetDraw(pIndex, pNumber)
   ' 字符数据字典
   If pIndex=-1 Then pIndex=9

   Dim DotData(9)
   DotData(0) = Array(30, 15, 50, 1, 50, 100)
   DotData(1) = Array(1 ,34 ,30 ,1 ,71, 1, 100, 34, 1, 100, 93, 100, 100, 86)
   DotData(2) = Array(1, 1, 100, 1, 42, 42, 100, 70, 50, 100, 1, 70)
   DotData(3) = Array(100, 73, 6, 73, 75, 6, 75, 100)
   DotData(4) = Array(100, 1, 1, 1, 1, 50, 50, 35, 100, 55, 100, 80, 50, 100, 1, 95)
   DotData(5) = Array(100, 20, 70, 1, 20, 1, 1, 30, 1, 80, 30, 100, 70, 100, 100, 80, 100, 60, 70, 50, 30, 50, 1, 60)
   DotData(6) = Array(6, 26, 6, 6, 100, 6, 53, 100)
   DotData(7) = Array(100, 30, 100, 20, 70, 1, 30, 1, 1, 20, 1, 30, 100, 70, 100, 80, 70, 100, 30, 100, 1, 80, 1, 70, 100, 30)
   DotData(8) = Array(1, 80, 30, 100, 80, 100, 100, 70, 100, 20, 70, 1, 30, 1, 1, 20, 1, 40, 30, 50, 70, 50, 100, 40)
   DotData(9) = Array(100, 20, 70, 1, 20, 1, 1, 30, 1, 80, 30, 100, 70, 100, 100, 80, 100, 60, 90, 20, 80,3)

   Dim vExtent : vExtent = Width / Count

   Margin(0) = Border + vExtent * (Rnd * Offset) / 100 + Margin(1)

   Margin(1) = vExtent * (pNumber + 1) - Border - vExtent * (Rnd * Offset) / 100

   Margin(2) = Border + Height * (Rnd * Offset) / 100

   Margin(3) = Height - Border - Height * (Rnd * Offset) / 100

   Dim vStartX, vEndX, vStartY, vEndY
   Dim vWidth, vHeight, vDX, vDY, vDeltaT
   Dim vAngle, vLength

   vWidth =Int(Margin(1) - Margin(0))
   vHeight =Int(Margin(3) - Margin(2))
   vStartX = Int((DotData(pIndex)(0)-1) * vWidth / 100)
   vStartY = Int((DotData(pIndex)(1)-1) * vHeight / 100)

   Dim i, j
   For i = 1 To UBound(DotData(pIndex), 1)/2
    If DotData(pIndex)(2*i-2) <> 0 And DotData(pIndex)(2*i) <> 0 Then
     vEndX = (DotData(pIndex)(2*i)-1) * vWidth / 100
     vEndY = (DotData(pIndex)(2*i+1)-1) * vHeight / 100
     vDX = vEndX - vStartX
     vDY = vEndY - vStartY
     If vDX = 0 Then
      vAngle = Sgn(vDY) * 3.14 /2
     Else
      vAngle = Atn(vDY / vDX)
     End If
     If Sin(vAngle) = 0 Then
      vLength = vDX
     Else
      vLength = vDY / Sin(vAngle)
     End If
     vAngle = vAngle + (Rnd - 0.5) * 2 * Angle * 3.14 * 2 / 100
     vDX = Int(Cos(vAngle) * vLength)
     vDY = Int(Sin(vAngle) * vLength)
     If Abs(vDX) > Abs(vDY) Then vDeltaT = Abs(vDX) Else vDeltaT = Abs(vDY)
     For j = 1 To vDeltaT
      SetDot Margin(0) + vStartX + j * vDX / vDeltaT, Margin(2) + vStartY + j * vDY / vDeltaT
     Next
     vStartX = vStartX + vDX
     vStartY = vStartY + vDY
    End If
   Next
  End Sub

  Public Sub Output()
   Response.Expires = -9999
   Response.AddHeader "pragma", "no-cache"
   Response.AddHeader "cache-ctrol", "no-cache"
   Response.ContentType = "image/gif"
   Response.BinaryWrite ChrB(Asc("G")) & ChrB(Asc("I")) & ChrB(Asc("F"))
   Response.BinaryWrite ChrB(Asc("8")) & ChrB(Asc("9")) & ChrB(Asc("a"))
   Response.BinaryWrite ChrB(Width Mod 256) & ChrB((Width 256) Mod 256)
   Response.BinaryWrite ChrB(Height Mod 256) & ChrB((Height 256) Mod 256)
   Response.BinaryWrite ChrB(128) & ChrB(0) & ChrB(0)
   Response.BinaryWrite ChrB(250) & ChrB(250) & ChrB(250)
   Response.BinaryWrite ChrB(0) & ChrB(0) & ChrB(0)
   Response.BinaryWrite ChrB(Asc(","))
   Response.BinaryWrite ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0)
   Response.BinaryWrite ChrB(Width Mod 256) & ChrB((Width 256) Mod 256)
   Response.BinaryWrite ChrB(Height Mod 256) & ChrB((Height 256) Mod 256)
   Response.BinaryWrite ChrB(0) & ChrB(7) & ChrB(255)

   Dim x, y, i : i = 0
   For y = 0 To Height - 1
    For x = 0 To Width - 1
     If Rnd < Noisy / 100 Then
      Response.BinaryWrite ChrB(1-Graph(x, y))
     ElseIf x * (x-Width) = 0 Or y * (y-Height) = 0 Then
      Response.BinaryWrite ChrB(Graph(x, y))
     ElseIf Graph(x-1, y) = 1 Or Graph(x, y) Or Graph(x, y-1) = 1 Then
      Response.BinaryWrite ChrB(1)
     Else
      Response.BinaryWrite ChrB(0)
     End If

     If (y * Width + x + 1) Mod 126 = 0 Then
      Response.BinaryWrite ChrB(128)
      i = i + 1
     End If
     If (y * Width + x + i + 1) Mod 255 = 0 Then
      If (Width*Height - y * Width - x - 1) > 255 Then
       Response.BinaryWrite ChrB(255)
      Else
       Response.BinaryWrite ChrB(Width * Height Mod 255)
      End If
     End If
    Next
   Next
   Response.BinaryWrite ChrB(128) & ChrB(0) & ChrB(129) & ChrB(0) & ChrB(59)
  End Sub
End Class
''''''''''''''''''''''''''''''''''''''''''''''''''''''

Dim mCode
Set mCode = New Com_GifCode_Class

    Randomize
    Dim code
    code = Int(Rnd * 9000 + 1000)
If showErrorImg Then
  Session("rCode_") = Int(Rnd * 9000 + 1000)
else
  Session("rCode_") = code
End If
mCode.Create2(code)
mCode.Output()
Set mCode = Nothing
</script>

补充：asp教程,高级应用