<%@ Page Language="vb" %>
<% 
Dim sMessage As String
Response.Clear()
      
Try


        Dim _Direction As String 'Horizontal or Vertical
        Dim _Length As Long
        Dim _StartColor As String
        Dim _EndColor As String
        Dim _Format As String

        sMessage = "retrieving parameters"
        _Direction = Request.QueryString.Item("Direction")
        _Length = Request.QueryString.Item("Length")
        _StartColor = Request.QueryString.Item("StartColor") '"#FF0000"
        _EndColor = Request.QueryString.Item("EndColor") '"#000000"
        _Format = Request.QueryString.Item("Format") '"JPEG"

        Dim lWidth As Integer
        Dim lHeight As Integer
        Dim m_Color1 As System.Drawing.Color
        Dim m_Color2 As System.Drawing.Color
        Dim myFormat As System.Drawing.Imaging.ImageFormat
        Dim myGradientMode As System.Drawing.Drawing2D.LinearGradientMode

        sMessage = "processing parameters"
        'Now use the parameters
        If _Direction.ToUpper.StartsWith("H") Then
            lWidth = 1
            lHeight = _Length
            myGradientMode = System.Drawing.Drawing2D.LinearGradientMode.Vertical
        Else
            lWidth = _Length
            lHeight = 1
            myGradientMode = System.Drawing.Drawing2D.LinearGradientMode.Horizontal
        End If
      
        Dim pngjpegorGif As String
        
        If _Format.ToUpper.StartsWith("J") Then
            myFormat = System.Drawing.Imaging.ImageFormat.Jpeg
            pngjpegorGif = "JPEG"
        ElseIf _Format.ToUpper.StartsWith("G") Then
            myFormat = System.Drawing.Imaging.ImageFormat.Gif
            pngjpegorGif = "GIF"
        Else
            myFormat = System.Drawing.Imaging.ImageFormat.Png
            pngjpegorGif = "PNG"
        End If

        sMessage = "determining colors"
        m_Color1 = System.Drawing.Color.FromArgb(255, CLng("&H" & _StartColor.Substring(0, 2)), CLng("&H" & _StartColor.Substring(2, 2)), CLng("&H" & _StartColor.Substring(4, 2)))
        m_Color2 = System.Drawing.Color.FromArgb(255, CLng("&H" & _EndColor.Substring(0, 2)), CLng("&H" & _EndColor.Substring(2, 2)), CLng("&H" & _EndColor.Substring(4, 2)))
        sMessage = "determining size"
        Dim bmpGradient As New System.Drawing.Bitmap(lWidth, lHeight)  'System.Drawing.Imaging.PixelFormat.DontCare)
        Dim m_BrushSize As New System.Drawing.Rectangle(0, 0, lWidth, lHeight)
        ' Get a Graphics object from the Bitmap for drawing.
        Dim grBitmap As System.Drawing.Graphics = System.Drawing.Graphics.FromImage(bmpGradient)
        sMessage = "creating gradient brush"
        Dim myLinearGradientBrush As New System.Drawing.Drawing2D.LinearGradientBrush( _
                            m_BrushSize, m_Color1, m_Color2, _
                            myGradientMode)
        sMessage = "filling rectangle"
        grBitmap.FillRectangle(myLinearGradientBrush, 0, 0, _
                 lWidth, lHeight)
        sMessage = "saving image to response stream"
        
        Dim MemStream As New System.IO.MemoryStream()
        
        bmpGradient.Save(MemStream, myFormat) ', New System.Drawing.Imaging.EncoderParameter(())
        
        
        Response.ContentType = "image/" + pngjpegorGif
        
        MemStream.WriteTo(Response.OutputStream)
        
        
    Catch Ex as System.Exception

	
        Dim bmpGradient As New System.Drawing.Bitmap(600, 100)   'System.Drawing.Imaging.PixelFormat.DontCare)
        Dim m_BrushSize As New System.Drawing.Rectangle(0, 0, 600, 100)
        ' Get a Graphics object from the Bitmap for drawing.
        Dim grBitmap As System.Drawing.Graphics = System.Drawing.Graphics.FromImage(bmpGradient)
        Dim myLinearGradientBrush As New System.Drawing.Drawing2D.LinearGradientBrush( _
                            m_BrushSize, System.Drawing.Color.FromArgb(255, 255, 0, 0), System.Drawing.Color.FromArgb(255, 0, 0, 0), _
                            System.Drawing.Drawing2D.LinearGradientMode.Vertical)
        grBitmap.FillRectangle(myLinearGradientBrush, 0, 0, _
          600, 100)
        grBitmap.DrawString("Error while " & sMessage & " for '" & Request.UserHostAddress & "'." & vbCrLf & Ex.Message, New System.Drawing.Font("Arial", 12, System.Drawing.FontStyle.Regular), System.Drawing.Brushes.White, 10, 12)
        bmpGradient.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Png)
    End Try
%>