How do I get data from the query string in asp?

Answer 1

It seems you just want:

string username = Request.QueryString["username"];

Answer 2

You can add a hidden field in your aspx file:

<asp:HiddenField ID="username" runat="server" />

And in your code behind populate it from the request parameter:

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        username.Value = Request["username"];
    }
}

Answer 3

This returns value from form elements :

string username = Request.Form["username"];

This returns value from querystring :

string username = Request.QueryString["username"];

This looks both form and querystring collections :

string username = Request["username"];