Add Column in GridView on Run Time using LINQ in ASP.Net

Hi nauna,

Refer below sample.

HTML

<asp:GridView runat="server" ID="GridView1" AutoGenerateColumns="false" 
    onrowdatabound="GridView1_RowDataBound">
    <Columns>
        <asp:BoundField DataField="CustomerId" HeaderText="CustomerId" />
        <asp:BoundField DataField="ContactName" HeaderText="ContactName" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
        <asp:TemplateField HeaderText="Rank">
            <ItemTemplate>
                <asp:Label ID="lblRank" runat="server" />
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        TestEntities entity = new TestEntities();
        var query = (from c in entity.TestCustomers
                        select c).ToList().Take(4);
        List<object> result = new List<object>();
        foreach (object item in query)
        {
            result.Add(item);
        }
        GridView1.DataSource = result;
        GridView1.DataBind();
    }
}

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        if (e.Row.Cells[0].Text == "AAFKM")
        {
            (e.Row.FindControl("lblRank") as Label).Text = "first";
        }
        else if (e.Row.Cells[0].Text == "ALFKI")
        {
            (e.Row.FindControl("lblRank") as Label).Text = "second";
        }
        else if (e.Row.Cells[0].Text == "ANATR")
        {
            (e.Row.FindControl("lblRank") as Label).Text = "third";
        }
        else if (e.Row.Cells[0].Text == "ANTON")
        {
            (e.Row.FindControl("lblRank") as Label).Text = "fourth";
        }
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        If Not Me.IsPostBack Then
            Dim entity As TestEntities = New TestEntities()
            Dim query = (From c In entity.TestCustomers Select c).ToList().Take(4)
            Dim result As List(Of Object) = New List(Of Object)()

            For Each item As Object In query
                result.Add(item)
            Next

            GridView1.DataSource = result
            GridView1.DataBind()
        End If
    End Sub

    Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
        If e.Row.RowType = DataControlRowType.DataRow Then

            If e.Row.Cells(0).Text = "AAFKM" Then
                (TryCast(e.Row.FindControl("lblRank"), Label)).Text = "first"
            ElseIf e.Row.Cells(0).Text = "ALFKI" Then
                (TryCast(e.Row.FindControl("lblRank"), Label)).Text = "second"
            ElseIf e.Row.Cells(0).Text = "ANATR" Then
                (TryCast(e.Row.FindControl("lblRank"), Label)).Text = "third"
            ElseIf e.Row.Cells(0).Text = "ANTON" Then
                (TryCast(e.Row.FindControl("lblRank"), Label)).Text = "fourth"
            End If
        End If
End Sub

Screenshot