Question

I have a really specific question for which I don’t think I will have an answer but… let’s try!
I have an aspx web page that works perfectly with Firefox and Chrome but not on IE9 (don’t feed the troll ^^).

My objective is to allow an asynchronous image upload using ASP AjaxControlToolkit (see http://www.asp.net/ajaxlibrary/AjaxControlToolkitSampleSite/asyncfileupload/asyncfileupload.aspx for a demo). When the image asynchronous upload is finished, the UploadedComplete function is called and I put the image in a session variable :

if (fileSizeOk && fileTypeOk)
        Session["image"] = this.AsyncFileUploadLogo.FileBytes;

In parallel I have a handler responsible for returning an image from the session variable :

byte[] buffer = (byte[])context.Session["image"];
context.Response.OutputStream.Write(buffer, 0, buffer.Length);
context.Response.OutputStream.Flush();

Then, in my aspx page, I have an asp:Image field in a UpdatePanel that asks to the handler to get the image every five second :

<asp:UpdatePanel ID="UpdatePanelLogo" runat="server">
    <ContentTemplate>  
        <asp:Image ID="ImageFileUploaded" runat="server" ImageUrl="AsyncImageHandler.ashx" />
        <asp:Timer ID="TimerFileUploaded" Interval="5000" runat="server" />
    </ContentTemplate>
</asp:UpdatePanel>

When the user validates the form, I just have to get the variable from the session and I save the image in database with the other values.

Here is my problem: with Firefox and Chrome, the timer provokes the reloading of the image but with IE (even IE9) the image is only displayed after hitting F5. When I put a breakpoint in the handler I can see that it’s never called with IE (maybe a caching mechanism?).

Do you have an idea of ​​how to solve this problem?

Thanks for your answers!

Answer 1

Found the solution using a classic Web dirty trick:

this.ImageFileUploaded.ImageUrl = "AsyncImageHandler.ashx?p=" + Environment.TickCount.ToString();

I added that line in the PageLoad(), this last is called on each post back triggered by the timer 🙂