How to use URL when an HttpHandler is not returning an Image?

Question

User2085410294 posted

Hi,

i am developing an application which has an httphandler. This httphandler returns an image which is shown by the application. But in case, that my httphandler doenst return an image (if the user hasnt one) i want to use an url. But dont know how.

This is my code:

Imports System
Imports System.IO
Imports System.DirectoryServices
Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.Web
Imports System.Web.SessionState
Imports Microsoft.SharePoint
Imports System.Web.UI

Public Class GetImage
    Implements IHttpHandler

    ''' <summary>
    '''  You will need to configure this handler in the web.config file of your
    '''  web and register it with IIS before being able to use it. For more information
    '''  see the following link: http://go.microsoft.com/?linkid=8101007
    ''' </summary>
#Region "IHttpHandler Members"

    Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
        Get
            ' Return false in case your Managed Handler cannot be reused for another request.
            ' Usually this would be false in case you have some state information preserved per request.

            ' Return False für SharePoint, true ist default
            Return False
        End Get
    End Property

    Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
                    Dim myimage As Byte() = DirectCast(user.Properties("uImage").Value, Byte())

                    If Not myimage Is Nothing Then
                        Dim mmStream As MemoryStream = New MemoryStream(myimage)
                        Dim img As Image = Image.FromStream(mmStream)

                        context.Response.Clear()
                        context.Response.ContentType = GetMimeType(img.RawFormat)
                        If GetMimeType(img.RawFormat).Equals("image/png") Or GetMimeType(img.RawFormat).Equals("image/bmp") Then
                            mmStream.WriteTo(context.Response.OutputStream)
                        Else
                            img.Save(context.Response.OutputStream, img.RawFormat)
                        End If
                        context.Response.End()
                    End If
    End Sub

#End Region

End Class



ASP.NET Page:

                    myPhoto.ImageUrl = "~/GetImage.ashx?user=" & GetCurrentUser()

The line above thould be call GetImage.ashx?user=xxx and if there is no image for the user, i want to show a static placeholder image.

best regards

yavuz