Show Hide add Button for LoggedIn user and Edit button for other users using C# and VB.Net in ASP.Net

Hi micah,

I have created sample code which full-fill your requirement. So please refer the code carefully and modify as per your requirement.

HTML

 Login Page

<form id="form1" runat="server">
<div>
    <table border="0" cellpadding="0" cellspacing="0">
        <tr>
            <td>
                UserName
            </td>
            <td>
                <asp:TextBox ID="txtUserName" runat="server" />
            </td>
        </tr>
        <tr>
            <td>
                Password
            </td>
            <td>
                <asp:TextBox ID="txtPassword" TextMode="Password" runat="server" />
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <asp:Button ID="btnSubmit" Text="Login" OnClick="OnLogin" runat="server" />
            </td>
        </tr>
    </table>
</div>
</form>

C#

protected void OnLogin(object sender, EventArgs e)
{
    string constring = ConfigurationManager.ConnectionStrings["constring"].ToString();
    using (SqlConnection con = new SqlConnection(constring))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT * FROM [User] WHERE UserName=@UserName AND Password=@Password", con))
        {
            cmd.Parameters.AddWithValue("@Username", txtUserName.Text.Trim());
            cmd.Parameters.AddWithValue("@Password", txtPassword.Text.Trim());
            con.Open();
            SqlDataReader idr = cmd.ExecuteReader();
            if (idr.Read())
            {
                Session["Id"] = idr["Id"].ToString();
                Response.Redirect("Default.aspx");
            }
            con.Close();
        }
    }
}

ViewPage

HTML

<form id="form1" runat="server">
<div>
    <asp:DataList ID="GetMergedAll" runat="server" RepeatColumns="4" OnItemDataBound="GetMergedAll_ItemDataBound">
        <HeaderTemplate>
            <table class="table" border="1">
                <tr>
                    <td>
                        <asp:Label ID="Label1" Text="Pics" runat="server" />
                    </td>
                    <td>
                        <asp:Label ID="Label2" Text="Action" runat="server" />
                    </td>
                </tr>
        </HeaderTemplate>
        <ItemTemplate>
            <tr>
                <td>
                    <asp:Label ID="Id" Text="0" Visible="false" runat="server" />
                    <asp:Label ID="lblUserId" Text='<%#Eval("UserId") %>' Visible="false" runat="server" />
                    <asp:ImageButton ID="UserImage" ImageUrl='<%# "Images/" + Eval("Name") %>' ToolTip='<%#Eval("Name")%>'
                        Width="80px" Height="50px" runat="server" />
                </td>
                <td>
                    <asp:LinkButton ID="btnAdd" Visible="false" runat="server">Add</asp:LinkButton>
                    <asp:LinkButton ID="btnEdit" Visible="false" runat="server">Edit</asp:LinkButton>
                </td>
            </tr>
        </ItemTemplate>
        <FooterTemplate>
            </table>
        </FooterTemplate>
    </asp:DataList>
</div>
<asp:LinkButton ID="linkback" OnClick="OnClick" Text="back" runat="server" />
</form>

C#

private string constring = ConfigurationManager.ConnectionStrings["constring"].ToString();
public string userId
{
    get
    {
        return Session["Id"].ToString() != null ? Convert.ToString(Session["Id"]) : "0";
    }
}

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.Populatebooks();
    }
}

private void Populatebooks()
{
    string Populatebooks = "SELECT * FROM [dbo].[Files]";
    using (SqlConnection con = new SqlConnection(constring))
    {
        con.Open();
        using (SqlCommand cmd = new SqlCommand(Populatebooks, con))
        {
            cmd.CommandType = CommandType.Text;
            SqlDataAdapter sda = new SqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            sda.Fill(dt);
            GetMergedAll.DataSource = dt;
            GetMergedAll.DataBind();
        }
    }
}

protected void GetMergedAll_ItemDataBound(object sender, DataListItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        string dlUserId = (e.Item.FindControl("lblUserId") as Label).Text;

        if (dlUserId == userId)
        {
            (e.Item.FindControl("btnEdit") as LinkButton).Visible = true;
        }
        else
        {

            (e.Item.FindControl("btnAdd") as LinkButton).Visible = true;
        }
    }
}

protected void OnClick(object sender, EventArgs e)
{
    Response.Redirect("LoginPage.aspx");
}

Vb.net

Login Page

Protected Sub OnLogin(sender As Object, e As EventArgs)
	Using con As New SqlConnection(constring)
		Using cmd As New SqlCommand("SELECT * FROM [User] WHERE UserName=@UserName AND Password=@Password", con)
			cmd.Parameters.AddWithValue("@Username", txtUserName.Text.Trim())
			cmd.Parameters.AddWithValue("@Password", txtPassword.Text.Trim())
			con.Open()
			Dim idr As SqlDataReader = cmd.ExecuteReader()
			If idr.Read() Then
				Session("Id") = idr("Id").ToString()
				Response.Redirect("Default.aspx")
			End If
			con.Close()
		End Using
	End Using
End Sub

ViewPage

Private constring As String = ConfigurationManager.ConnectionStrings("constring").ToString()
Public ReadOnly Property userId() As String
	Get
		Return If(Session("Id").ToString() IsNot Nothing, Convert.ToString(Session("Id")), "0")
	End Get
End Property

Protected Sub Page_Load(sender As Object, e As EventArgs)
	If Not Me.IsPostBack Then
		Me.Populatebooks()
	End If
End Sub

Private Sub Populatebooks()
	Dim Populatebooks As String = "SELECT * FROM [dbo].[Files]"
	Using con As New SqlConnection(constring)
		con.Open()
		Using cmd As New SqlCommand(Populatebooks, con)
			cmd.CommandType = CommandType.Text
			Dim sda As New SqlDataAdapter(cmd)
			Dim dt As New DataTable()
			sda.Fill(dt)
			GetMergedAll.DataSource = dt
			GetMergedAll.DataBind()
		End Using
	End Using
End Sub

Protected Sub GetMergedAll_ItemDataBound(sender As Object, e As DataListItemEventArgs)
	If e.Item.ItemType = ListItemType.Item OrElse e.Item.ItemType = ListItemType.AlternatingItem Then
		Dim dlUserId As String = TryCast(e.Item.FindControl("lblUserId"), Label).Text

		If dlUserId = userId Then
			TryCast(e.Item.FindControl("btnEdit"), LinkButton).Visible = True
		Else

			TryCast(e.Item.FindControl("btnAdd"), LinkButton).Visible = True
		End If
	End If
End Sub

Protected Sub OnClick(sender As Object, e As EventArgs)
	Response.Redirect("LoginPage.aspx")
End Sub

Screenshot