Problem with Download and upload feature while in update panel.

[pratsadhu]

Hi,

I have an update panel with a dropdown list. On index change, values will be populated from databas. The dropdownlist and the table are placed in an update panel. Now, i have added another table with download and upload features. if i try to put these button in the update panel an error is raised saying:
" Response method has been modified or Server trace is enabled.
My requiremet needs the download feature to be visible only the selected index change. How do I avoid the error?'


Thanks

[Frinavale]

I'm not sure what you are trying to do...
You have a DropDownList and then when a user selects an item you Repopulate the DropDownList with something else?

Could you please post your code so that I can better understand what you're doing?

[pratsadhu]

Here I have a DropDownList ddlHoldingComp and a gridview gvTraining
On DropDownList SelectedIndexch ange, the grid view will be updated and the upload download buttons will be visible.
Now if i put the upload download buttons in UpdatePanel, and try to download a file the Aspx page throws an error saying
"The Response has been changed or server trace has been enabled".

Following is my code.


[code=asp]
<asp:UpdatePane l ID="UpdatePanel 1" runat="server">
<contenttemplat e>
<table>
<tr>
<td>
<asp:UpdatePane l ID="UpdatePanel 9" runat="server">
<contenttemplat e>
<table id="tblLookup" cellspacing="0" cellpadding="5" width="100%" border="0" runat="server">
<tr>
<td align="left" width="73%">
<asp:DropDownLi st ID="ddlHoldingC omp" runat="server" AutoPostBack="t rue"
Width="45%" OnSelectedIndex Changed="ddlHol dingComp_Select edIndexChanged" >
</asp:DropDownLis t>
</td>
</tr>

</table>
</contenttemplate >
</asp:UpdatePanel >
</td>
</tr>
<tr>
<td>
<asp:UpdatePane l ID="UpdatePanel 7" runat="server">
<contenttemplat e>

<table width="100%" border="0" cellpadding="0" cellspacing="5" visible="false" >
<tr align="left" valign="top">
<td>
<asp:GridView ID="gvTraining " BorderColor="Da rkGray" runat="server" Width="98%" CellPadding="5"
HeaderStyle-CssClass="table-head3" AlternatingRowS tyle-BackColor="#e1e 1e1" HorizontalAlign ="Left"
AutoGenerateCol umns="False" >
<Columns>
<asp:TemplateFi eld HeaderText="Sel ect">
<ItemTemplate >
<asp:RadioButto n ID="rbtnSelect " runat="server" onClick="ShowHi deControls(this )"></asp:RadioButton >
</ItemTemplate>
<HeaderStyle HorizontalAlign ="center" BorderColor="Da rkGray" />
<ItemStyle BorderColor="Da rkGray" HorizontalAlign ="Center" VerticalAlign=" top">
</ItemStyle>
</asp:TemplateFie ld>
<asp:BoundFie ld DataField="Desc ription" HeaderText="Tra inings" HeaderStyle-HorizontalAlign ="Center"
HtmlEncode="fal se">
<ItemStyle CssClass="field stext" BorderColor="Da rkGray" HorizontalAlign ="left" Width="90%">
</ItemStyle>
</asp:BoundField>
</Columns>
<HeaderStyle CssClass="table-head3" BorderColor="Da rkGray"></HeaderStyle>
<AlternatingRow Style BackColor="#E1E 1E1"></AlternatingRowS tyle>
</asp:GridView>
</td>
</tr>
</table>

</contenttemplate >
</asp:UpdatePanel >
</td>
</tr>
<tr>
<td>
<asp:UpdatePane l ID="UpdatePanel 2" runat="server">
<contenttemplat e>
<table border="0" width="90%" cellpadding="5" cellspacing="0" style="border-color: Gray;" id="tblUpload" runat="server" visible=false>
<tr valign="middle" >
<td width="31%" align="left" valign="top">

<asp:LinkButt on runat="server" SkinID="lbtnSki n" ID="ibtnDownloa d" Text="Text"
OnClick="ibtnDo wnload_Click"></asp:LinkButton>

</td>
</tr>

<tr>
<td colspan="2" valign="top">
<asp:FileUplo ad ID="fileUpload " runat="server" Width="98%"></asp:FileUpload>
</td>
<td align="left">

<asp:ImageButto n ID="ibtnUpload " runat="server" BorderWidth="0" ImageUrl="~/Images/upload-but.gif"
OnClick="ibtnUp load_Click" OnClientClick=" ValidateUpload( )"></asp:ImageButton >
</td>
</tr>
</table>
</contenttemplate >
</asp:UpdatePanel >
</td>

</tr>
</table>
</contenttemplate >
</asp:UpdatePanel >[/code]