Question

I have a website that uses form authentication. For some reason it works fine at the first run. But on the second run it says too many redirects error.

Loginpage:Load event

 protected void Page_Load(object sender, EventArgs e)
            {
                if (Request.IsAuthenticated)
                {
                    Response.Redirect("HomePage.aspx");
                }

            }

Login Page submit credentials

 protected void btnSubmit_Click(object sender, EventArgs e)
        {
           int recordExistCount = fc.Authenticate(txtUsername.Text.Trim(), txtPassword.Text.Trim());
           if (recordExistCount == 1)
           {
               Session["User"] = "Authenticated";
               Session["Username"] = txtUsername.Text.Trim();
               fc.IsOnlineRecord(Session["Username"].ToString(),true);
               FormsAuthentication.RedirectFromLoginPage(Session["Username"].ToString(), true);
               Response.Redirect("HomePage.aspx");
           }
           else
           {
               lblStatus.Text = "Username or password specified are incorrect";
               lblStatus.BackColor = Color.Yellow;               
           }
        }

Masterpage signout button

protected void lbSignOut_Click(object sender, EventArgs e)
        {
            Session.Abandon();
            FormsAuthentication.SignOut();
            Response.Redirect("LoginPage.aspx");
        }

Answer 1

Try this

On LoginPage.aspx

protected void Page_Load(object sender, EventArgs e)
{
    if (Request.QueryString["action"] != null && Request.QueryString["action"] == "logout")
    {
        Session.Abandon();
        FormsAuthentication.SignOut();
    }
    else
    {
        if (HttpContext.Current.User.IsAuthenticated)
        {
            Response.Redirect("HomePage.aspx");
        }
    }
}

protected void btnSubmit_Click(object sender, EventArgs e)
{
    int recordExistCount = fc.Authenticate(txtUsername.Text.Trim(), txtPassword.Text.Trim());
    if (recordExistCount == 1)
    {
        Session["User"] = "Authenticated";
        Session["Username"] = txtUsername.Text.Trim();
        fc.IsOnlineRecord(Session["Username"].ToString(), true);
        FormsAuthentication.RedirectFromLoginPage(Session["Username"].ToString(), true);
    }
    else
    {
        lblStatus.Text = "Username or password specified are incorrect";
        lblStatus.BackColor = Color.Yellow;
    }
}

And on MasterPage Markup, place an asp:LoginStatus like this

<asp:LoginStatus ID="AdminLoginStatus" runat="server" 
        LogoutAction="RedirectToLoginPage" 
        LogoutText="Log Out" 
        LogoutPageUrl="~/LoginPage.aspx?action=logout"/>