Show Button when user is Logged In using C# and VB.Net in ASP.Net

Hi sha10oct,

Refer below sample.

HTML

Login.aspx

Name :
<asp:TextBox runat="server" ID="txtName" />
<br />
<asp:Button Text="Login" runat="server" OnClick="LoginData" />

CS.aspx

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="Name" HeaderText="File Name" />
        <asp:TemplateField ItemStyle-HorizontalAlign="Center" Visible="false">
            <ItemTemplate>
                <asp:LinkButton ID="lnkDownload" runat="server" Text="Download" CommandArgument='<%# Eval("Id") %>'></asp:LinkButton>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField ItemStyle-HorizontalAlign="Center" Visible="false">
            <ItemTemplate>
                <asp:LinkButton ID="lnkView" runat="server" Text="View" CommandArgument='<%# Eval("Id") %>'></asp:LinkButton>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

Namespaces

C#

using System.Data.SqlClient;
using System.Configuration;

VB.Net

Imports System.Data.SqlClient
Imports System.Configuration

Code

C#

LoginCS.aspx.cs

protected void LoginData(object sender, EventArgs e)
{
    // Code for Login.
    Session["IsLogin"] = true;
    Response.Redirect("CS.aspx");
}

CS.aspx.cs

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        BindGrid();

        bool IsLoggedIn = Session["IsLogin"] != null ? Convert.ToBoolean(Session["IsLogin"]) : false;
        if (IsLoggedIn)
        {
            GridView1.Columns[1].Visible = true;
            GridView1.Columns[2].Visible = true;
        }
        else
        {
            GridView1.Columns[1].Visible = false;
            GridView1.Columns[2].Visible = false;
        }
    }
}

private void BindGrid()
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand())
        {
            cmd.CommandText = "select Id, Name from tblFiles";
            cmd.Connection = con;
            con.Open();
            GridView1.DataSource = cmd.ExecuteReader();
            GridView1.DataBind();
            con.Close();
        }
    }
}

LoginVB.cs

Protected Sub LoginData(ByVal sender As Object, ByVal e As EventArgs)
    Session("IsLogin") = True
    Response.Redirect("CS.aspx")
End Sub

VB.aspx.vb

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not IsPostBack Then
        BindGrid()
        Dim IsLoggedIn As Boolean = If(Session("IsLogin") IsNot Nothing, Convert.ToBoolean(Session("IsLogin")), False)
        If IsLoggedIn Then
            GridView1.Columns(1).Visible = True
            GridView1.Columns(2).Visible = True
        Else
            GridView1.Columns(1).Visible = False
            GridView1.Columns(2).Visible = False
        End If
    End If
End Sub

Private Sub BindGrid()
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(constr)
        Using cmd As SqlCommand = New SqlCommand()
            cmd.CommandText = "select Id, Name from tblFiles"
            cmd.Connection = con
            con.Open()
            GridView1.DataSource = cmd.ExecuteReader()
            GridView1.DataBind()
            con.Close()
        End Using
    End Using
End Sub

Screenshot