asked on

Control must be placed inside a form tag

Getting this error...

Control 'mygridview' of type 'GridView' must be placed inside a form tag with runat=server.

I dynamically take a gridview, stored in a session var, and put it in the form's controls collection. Why am I getting this error?

Dim stw As New System.IO.StringWriter()
Dim htextw As New HtmlTextWriter(stw)            
Dim mygridview As New GridView

mygridview = CType(Session("GridViewToExport"), GridView)
form1.Controls.Add(mygridview)

'render gridview control to excel
 mygridview.RenderControl(htextw) ' ERROR OCCURS HERE

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guru_sami

Use PlaceHolder control to do that.
Add a PlaceHolder Control on the page where you want the GV to appear.
Then add gv to this ph.
e.g.

<asp:PlaceHolder ID="PlaceHolder1" runat="server" />

PlaceHolder1.Controls.Add(mygridview)

e.g.:http://blog.krisvandermast.com/AddingADynamicControlToAPlaceholderControlAndWireUpTheEvent.aspx

RobertNZana

ASKER

Same exact error, even when using the placeholder solution.

It happens on the rendercontrol line.

ASKER CERTIFIED SOLUTION

timexist

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RobertNZana

ASKER

Thanks. Seems to work well.

But when Excel opens the file it says "The file you are trying to open, xxxx.xls, is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a trusted source before opening the file. Do you wat to open the file now?"

Do you know what this means?