How to expire session after clicking on logout

.NET
1

Hello, m using c# .asp.net and oracle databse.
I’ve been trying to expire the session after the user logs out of my site. I have a “logout” button in the site. Is there any way I could make the user unable to go back to the page without logging in again after clicking the logout button. After clicking on logout m redirecting to login page…
what and where to write for this.
Please help.

2

In logout.aspx page, write the following code :

Session.Clear();
Session.Abandon();
Response.Redirect(“Login.aspx”,true);

3

It’s working but in some forms m getting error.
object reference not set to an instance of an object.
This error is coming on the pages where m using session in page_load event.
like i have one form addsubcategory.aspx.
In that i have written d following code.
Do read commented line.

protected void Page_Load(object sender, EventArgs e)
{

    if (!IsPostBack)
    {
        try
        {

           // btnAdd.Attributes.Add("onclick", "return Validate('" + ddlCategory.ClientID + "','" + ddlSeverityType.ClientID + "')");
            //btnAdd.Attributes.Add("onclick", "javascript:return isNumeric();");
            //btnAdd.Attributes.Add("onclick", "return isNumeric('" + txtSubcategoryName.ClientID + "','" + ddlCategory.ClientID + "')");

            btnAdd.Attributes.Add("onclick", "return Valid('" + txtSubcategoryName.ClientID + "','" + ddlCategory.ClientID + "','" + ddlSeverityType.ClientID + "')");
            txtSubcategoryName.Focus();

            BLSubcategory objSubcategory = new BLSubcategory();
            string supId = string.Empty;
            supId = Session["USERNAME"].ToString();//here m getting error
            dsCategory = objSubcategory.GetCategory(supId);
            dsSeverity = objSubcategory.GetSeverity(supId);
            DataRow dr = dsCategory.Tables[0].NewRow();
            DataRow dt = dsSeverity.Tables[0].NewRow();
            dr["Category_Name"]= "Select Category";
            dr["Category_Id"] = "0";
            dsCategory.Tables[0].Rows.InsertAt(dr, 0);
            ddlCategory.DataSource = dsCategory;
            ddlCategory.DataTextField = "Category_Name";
            ddlCategory.DataValueField = "Category_Id";
            ddlCategory.DataBind();
            dt["Severity_Type"]="0";
            dt["Severity_Id"] = "0";
            dsSeverity.Tables[0].Rows.InsertAt(dt,0);
            ddlSeverityType.DataSource = dsSeverity;
            ddlSeverityType.DataTextField = "Severity_Type";
            ddlSeverityType.DataValueField = "Severity_Id";
            ddlSeverityType.DataBind();

        }

        catch (Exception ex)
        {
            throw ex;//here it says object ref not set to an instance of an obj.
        }
        LoadSubcategory();

    }
}
4

Hi,

I have a “logout” button in the site.

On logout button click event you have to write
Session.Clear();
Session.Abandon();
Response.Redirect(“Login.aspx”,true);

thanks,
kunalraj

5

Are you using forms authentication? If so, do it like this:

Session.Clear();
Session.Abandon();
FormsAuthentication.SignOut();
Response.Redirect(“Login.aspx”);

6

It’s working…thanks.