How to remove a Gridview from an ASPX page? - asp.net

Question

I have an Aspx page that displays a GridView. The gridview would appear with data that was depending on which catergory was selected from a drop down menu. The user has the option to then download this as a CSV file (export to CSV). I now want the Gridview not to appear (beacuse it is so large it often just hangs) but instead to be able to download a CSV file with the data from the gridview. I have successfully built the button allowing for the download of this data by clicking the button. However, I now cannot open the page without the gridView appearing. I tried to comment out the Gridview code - this just broke the page. I tried to set the gridview as Visible="False" but this did not work either. What else can I do to prevent the gridview from appearing and the user to be taken straight to a download dialogue box?

Answer 1

wrap your Gridview to a div and set it to display:none in asp.net code –
Ex: <div id="divhidegrid" runat="server" style="display:none;" > <asp:GridView ID="gvtest" runat="server" > </div> like this

Answer 2

You can load your data in DataSet or DataTable from Code Behind and then export it directly to Excel/CSV without assigning it to GridView such as in the following example to export it to Excel:
Public Sub ExportToExcel(dt As DataTable)
If dt.Rows.Count > 0 Then
Dim tw As New System.IO.StringWriter()
Dim hw As New System.Web.UI.HtmlTextWriter(tw)
Dim dgGrid As New DataGrid()
dgGrid.DataSource = dt
dgGrid.DataBind()
'Get the HTML for the control.
dgGrid.RenderControl(hw)
'Write the HTML back to the browser.
Response.ContentType = "application/vnd.ms-excel"
Response.AppendHeader("Content-Disposition", "attachment; filename=Data.xls")
Me.EnableViewState = False
Response.Write(tw.ToString())
Response.[End]()
End If
End Sub
If you get errors like control must be placed in inside of form tag you may also be required put the following code in your backend (Reference: export-data-to-excel-from-datatable-gridview-aspnet-csharp)
Public Sub VerifyRenderingInServerForm(control As Control)
' Verifies that the control is rendered
End Sub
C# Version of above code:
public void ExportToExcel(DataTable dt)
{
if (dt.Rows.Count > 0) {
System.IO.StringWriter tw = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter(tw);
DataGrid dgGrid = new DataGrid();
dgGrid.DataSource = dt;
dgGrid.DataBind();
//Get the HTML for the control.
dgGrid.RenderControl(hw);
//Write the HTML back to the browser.
Response.ContentType = "application/vnd.ms-excel";
Response.AppendHeader("Content-Disposition", "attachment; filename=Data.xls");
this.EnableViewState = false;
Response.Write(tw.ToString());
Response.End();
}
}
public void VerifyRenderingInServerForm(Control control)
{
// Verifies that the control is rendered
}