Gridding .NET

export datagrid to excel

this code can be run outside of page, or can be converted to run in and extended datagrid control

imports System.Drawing
Imports System.Web.UI
Imports System.Web.UI.WebControls

Namespace demetz

    Public Class DemExportGridExcel

        Sub RenderGridToExcelFormat(ByVal grid As DataGrid, ByVal saveAsFile As String)
            ' check Excel rows limit
            If grid.Items.Count.ToString + 1 < 65536 Then
                HttpContext.Current.Response.Clear()
                HttpContext.Current.Response.ContentType = "application/vnd.ms-excel"
                HttpContext.Current.Response.AddHeader("content-disposition", "attachment;filename=" & saveAsFile & ".xls")
                ' Remove the charset from the Content-Type header.
                HttpContext.Current.Response.Charset = ""
                'HttpContext.Current.Response.WriteFile("style.txt")
                ' Turn off the view state.
                grid.EnableViewState = False
                Dim tw As New System.IO.StringWriter()
                Dim hw As New System.Web.UI.HtmlTextWriter(tw)
                ' Get the HTML for the control.
                grid.HeaderStyle.ForeColor = Color.Black
                grid.HeaderStyle.BackColor = Color.Red
                grid.ItemStyle.ForeColor = Color.Black
                grid.BorderColor = Color.White
                ClearControls(grid)
                grid.RenderControl(hw)
                ' Write the HTML back to the browser.
                HttpContext.Current.Response.Write(tw.ToString())
                ' End the response.
                HttpContext.Current.Response.End()
            Else
               
                HttpContext.Current.Response.Write("Too many rows - Export to Excel not possible")
            End If
        End Sub

        Sub ClearControls(ByVal control As Control)
            Dim i As Integer
            For i = control.Controls.Count - 1 To 0 Step -1
                ClearControls(control.Controls(i))
            Next i

            If TypeOf control Is System.Web.UI.WebControls.Image Then
                control.Parent.Controls.Remove(control)
            End If

            If (Not TypeOf control Is TableCell) Then
                If Not (control.GetType().GetProperty("SelectedItem") Is Nothing) Then
                    Dim literal As New LiteralControl()
                    control.Parent.Controls.Add(literal)
                    Try
                        literal.Text = CStr(control.GetType().GetProperty("SelectedItem").GetValue(control, Nothing))
                    Catch
                    End Try
                    control.Parent.Controls.Remove(control)
                Else
                    If Not (control.GetType().GetProperty("Text") Is Nothing) Then
                        Dim literal As New LiteralControl()
                        control.Parent.Controls.Add(literal)
                        literal.Text = CStr(control.GetType().GetProperty("Text").GetValue(control, Nothing))
                        control.Parent.Controls.Remove(control)
                    End If
                End If
            End If
            Return
        End Sub 'ClearControls

    End Class

End Namespace