asp无组件生成验证码 GIF图片格式

<%
Option Explicit ' 显示声明
Class Com_GifCode_Class
'''''''''''''''''''''''''''''''''''''''''''''
' Author: Layen support@ssaw.net 84815733(QQ)
' Thanks: Laomi, Laomiao, NetRube
' 2006-01-02
'''''''''''''''''''''''''''''''''''''''''''''
Public Noisy, Count, Width, Height, Angle, Offset, Border
Private Graph(), Margin(3)
Private Sub Class_Initialize()
Randomize
Noisy = 16 ' 干扰点出现的概率
Count = 4 ' 字符数量
Width = 80 ' 图片宽度
Height = 20 ' 图片高度
Angle = 2 ' 角度随机变化量
Offset = 20 ' 偏移随机变化量
Border = 1 ' 边框大小
End Sub
Public Function Create()
Const cCharSet = "123456789"
Dim i, x, y
Dim vValidCode : vValidCode = ""
Dim vIndex
ReDim Graph(Width-1, Height-1)
For i = 0 To Count - 1
vIndex = Int(Rnd * Len(cCharSet))
vValidCode = vValidCode + Mid(cCharSet, vIndex+1 , 1)
SetDraw vIndex, i
Next
Create = vValidCode
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
Dim DotData(8)
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)
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))
' 起始坐标
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
' 终点坐标
vEndX = (DotData(pIndex)(2*i)-1) * vWidth / 100
vEndY = (DotData(pIndex)(2*i+1)-1) * vHeight / 100
' 横向差距
vDX = vEndX - vStartX
' 纵向差距