Question

I’m working in ASP.NET c# application.
I came to a part where I need to retain some value after response.redirect to the same page without using additional QueryString or Session, because Session more or less may burden the server’s performance even just a small value.

Below is my code fragment:

 protected void ddl_SelectedIndexChanged(object sender, EventArgs e)
 {
string id = ddl.SelectedValue;
string id2 = ddl2.SelectedValue;
Response.Redirect("http://sharepoint2007/sites/home/Lists/CustomList/DispForm.aspx?ID=" + id);
 }

I wanted to retain the value id2 after the Response.Redirect, I’ve tried ViewState but seem like after the redirect, it treat the page as new page and ViewState value gone.

Update:

My intention to retain the value after redirect is wanted to bind back the dropdownlist selected value.

Please help.

Thank you in advanced.

Answer 1

using cookies will do the trick:

protected void ddl_SelectedIndexChanged(object sender, EventArgs e)
{
    string id = ddl.SelectedValue;
    string id2 = ddl2.SelectedValue;
    HttpCookie cookie = new HttpCookie("SecondId", id2);
    Response.Cookies.Add(cookie);
    Response.Redirect("http://sharepoint2007/sites/home/Lists/CustomList/DispForm.aspx?ID=" + id);
}

protected void OnLoad(object sender, EventArgs e)
{
    string id2 = Request.Cookies["SecondId"];
    //send a cookie with an expiration date in the past so the browser deletes the other one
    //you don't want the cookie appearing multiple times on your server
    HttpCookie clearCookie = new HttpCookie("SecondId", null);
    clearCookie.Expires = DateTime.Now.AddDays(-1);
    Response.Cookies.Add(clearCookie);
}