asp无组件生成验证码 GIF图片格式

复制代码 代码如下:

  <%

  Option Explicit ' 显示声明

  Class Com_GifCode_Class

  '''''''''''''''''''''''''''''''''''''''''''''

  ' Author: Layen [email protected] 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

  vDY = vEndY - vStartY

  ' 倾斜角度

  If vDX = 0 Then

  vAngle = Sgn(vDY) * 3.14/2

  Else

  vAngle = Atn(vDY / vDX)

  End If

  ' 两坐标距离

  If Sin(vAngle) = 0 Then

  vLength = vDX

  Else

  vLength = vDY / Sin(vAngle)

  End If

  ' 随机转动角度

  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"

  ' 文件类型

  Response.BinaryWrite ChrB(Asc("G")) & ChrB(Asc("I")) & ChrB(Asc("F"))

  ' 版本信息

  Response.BinaryWrite ChrB(Asc("8")) & ChrB(Asc("9")) & ChrB(Asc("a"))

  ' 逻辑屏幕宽度

  Response.BinaryWrite ChrB(Width Mod 256) & ChrB((Width \ 256) Mod 256)

  ' 逻辑屏幕高度

  Response.BinaryWrite ChrB(Height Mod 256) & ChrB((Height \ 256) Mod 256)

  Response.BinaryWrite ChrB(128) & ChrB(0) & ChrB(0)

  ' 全局颜色列表

  Response.BinaryWrite ChrB(255) & ChrB(255) & ChrB(255)

  Response.BinaryWrite ChrB(0) & ChrB(85) & ChrB(255)

  ' 图象标识符

  Response.BinaryWrite ChrB(Asc(","))

  Response.BinaryWrite ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0)

  ' 图象宽度

  Response.BinaryWrite ChrB(Width Mod 256) & ChrB((Width \ 256) Mod 256)

  ' 图象高度

  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))

  Else

  If x * (x-Width) = 0 Or y * (y-Height) = 0 Then

  Response.BinaryWrite ChrB(Graph(x, y))

  Else

  If 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

  End If

  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

  Session("GetCode") = mCode.Create()

  mCode.Output()

  Set mCode = Nothing

  %>