Control 'GridView1' of type 'GridView' must be placed inside a form tag with runat=server

Question

Control 'GridView1' of type 'GridView' must be placed inside a form tag with runat=server.

When I export the Gridview to Excel, I get an error like this. Can you help me?

My code example is as follows.

 Dim SqlQuery As String = "SELECT * FROM vBasketbollTournamet ORDER BY 1 ASC"

 Dim cmd1 As New SqlCommand(SqlQuery, conn)
 Dim adp1 As New SqlDataAdapter(cmd1)
 adp1.Fill(dt2)

 GridView1.DataSource = dt2
 GridView1.DataBind()


 Dim oStringWriter As New StringWriter()
 Dim oHtmlTextWriter As New HtmlTextWriter(oStringWriter)

 GridView1.GridLines = GridLines.Horizontal
 GridView1.HeaderStyle.Font.Bold = True
 GridView1.RenderControl(oHtmlTextWriter)

 Response.Write(oStringWriter.ToString())
 Response.[End]()

Answer 1

I think, you can use below the example.

.aspx file contens

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    </div>
    <asp:GridView ID="GridView1" runat="server">
    </asp:GridView>
    <br />
    <asp:Button ID="btntoExcel" runat="server" Text="GridView to Excel" onclick="btntoExcel_Click" />
    </form>
</body>
</html>

.aspx.vb file contents

Imports System.Drawing
Imports System.Data.SqlClient
Imports System.Data
Partial Class _Default
    Inherits System.Web.UI.Page
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim adapter As New SqlDataAdapter()
        Dim ds As New DataSet()
        Dim i As Integer = 0
        Dim sql As String = Nothing
        Dim connetionString As String = "Data Source=.;Initial Catalog=pubs;User ID=sa;Password=*****"
        sql = "select * from stores"
        Dim connection As New SqlConnection(connetionString)
        connection.Open()
        Dim command As New SqlCommand(sql, connection)
        adapter.SelectCommand = command
        adapter.Fill(ds)
        adapter.Dispose()
        command.Dispose()
        connection.Close()
        GridView1.DataSource = ds.Tables(0)
        GridView1.DataBind()
    End Sub
    Protected Sub btntoExcel_Click(ByVal sender As Object, ByVal e As EventArgs)
        Response.ClearContent()
        Response.AddHeader("content-disposition", "attachment; filename=gvtoexcel.xls")
        Response.ContentType = "application/excel"
        Dim sw As New System.IO.StringWriter()
        Dim htw As New HtmlTextWriter(sw)
        GridView1.RenderControl(htw)
        Response.Write(sw.ToString())
        Response.[End]()
    End Sub
    Public Overrides Sub VerifyRenderingInServerForm(ByVal control As Control)
        'Tell the compiler that the control is rendered
        'explicitly by overriding the VerifyRenderingInServerForm event.
    End Sub
  End Class

Control 'GridView1' of type 'GridView' must be placed inside a form tag with runat=server

Question

1 answers

solution1
2 ACCPTED 2017-04-05 13:39:45

Control 'GridView1' of type 'GridView' must be placed inside a form tag with runat=server

Question

1 answers

solution1 2 ACCPTED 2017-04-05 13:39:45

solution1
2 ACCPTED 2017-04-05 13:39:45