Using an asp:UpdatePanel to Trigger vb code to save picture into a database

Hi,
I have a button and an input type=file box.  This uses some vb code to convert a picture so I can save it into a database image column.  This all works fine.  If I add an update panel around it with a asp:PostBackTrigger again it works fine but is still jumping for the user.  If I use a asp:AsyncPostBackTrigger it breaks on the following line.

intImageSize = File2.PostedFile.ContentLength

This is the error I recieve.

System.NullReferenceException was unhandled by user code
  Message=Object reference not set to an instance of an object.
  Source=App_Web_kxfoj2ur
  StackTrace:
       at Create_Brief.Button4_Click(Object sender, EventArgs e) in C:\Documents and Settings\newcoc01\My Documents\Visual Studio 2010\WebSites\20120327\Create_Brief.aspx.vb:line 550
       at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
       at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
       at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
       at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
       at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
       at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
  InnerException:

 Protected Sub Button4_Click(sender As Object, e As System.EventArgs) Handles Button4.Click

        '**** Resize image section ****  File2
        Dim strImageType As String
        Dim intImageSize As Int64
        Dim ImageStream As Stream

        ' Gets the Size of the Image
        intImageSize = File2.PostedFile.ContentLength

        ' Gets the Image Type
        strImageType = File2.PostedFile.ContentType

        ' Reads the Image
        ImageStream = File2.PostedFile.InputStream

Open in new window


Does anyone know why this happens and how I can get this working?
morantAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Lalit ChandraCommented:
This problem is somewhat well documented, the update panel is listed as not working with certain controls.

File upload, and tree view being 2 of the biggies.

IN any case, one solution is available on code project:

http://www.codeproject.com/useritems/simpleajaxupload.asp

if you look around the forums and google, you can read more about the problem if your interested, but the code project solution should get you started.

Hope this will guide you to solve your problem.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Scripting Languages

From novice to tech pro — start learning today.