Ho finalmente risolto.
Ho modificato l'Handler in questo modo:
<%@ WebHandler Language="VB" Class="ImageFetch" %>
Imports System.Web
Imports System.Data.SqlClient
Imports System.Data
'The idea behind this is to simply fetch the image out of the database and stream it down the network.
Public Class ImageFetch : Implements IHttpHandler
Const BUFFERSIZE As Integer = 1024
Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
Get
Return True
End Get
End Property
Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
Dim response As Web.HttpResponse = context.Response
Dim request As Web.HttpRequest = context.Request
response.ContentType = "image/jpeg"
response.Cache.SetCacheability(HttpCacheability.Public)
response.BufferOutput = False
writeSingleImage(CInt(request.QueryString("ImageID")), CInt(request.QueryString("Size")), response.OutputStream)
response.End()
End Sub
Public Sub writeSingleImage(ByVal ImageID As Integer, ByVal size As Integer, ByVal output As IO.Stream)
'todo fix the following line of code
Dim cxnstr As String = ConfigurationManager.ConnectionStrings("your connection string").ConnectionString
Dim connection As New SqlConnection(cxnstr)
Dim query As String
query = "select imgData from imagePreview where imgid=@item_id"
Dim command As New SqlCommand(query, connection)
Dim param0 As New Data.SqlClient.SqlParameter("@item_id", Data.SqlDbType.Int)
param0.Value = ImageID
command.Parameters.Add(param0)
connection.Open()
Dim d As Byte() = CType(command.ExecuteScalar(), Byte())
output.Write(d, 0, d.Length)
connection.Close()
End Sub
End Class
e l'ho richiamato in questo modo:
<asp:Image ID="ImageButton1" ImageUrl='<%# "imagefetch.ashx?size=1&imageid=" & Cstr(Eval("imgId")) %>' runat ="server" Height="100px" BorderColor="Black" BorderStyle="Solid" BorderWidth="1px"/>
Grazie ancora Amelix
Marco
