Returns a System.Collections.Specialized.NameValueCollection of data posted back to the page using either a POST or a GET command.
A System.Collections.Specialized.NameValueCollection object that contains the form data. If the postback used the POST command, the form information is returned from the Page.Context object. If the postback used the GET command, the query string information is returned. If the page is being requested for the first time, null is returned.
The Page.DeterminePostBackMode method returns a System.Collections.Specialized.NameValueCollection object that contains the data posted back to the page. The presence of the page hidden fields VIEWSTATE and EVENTTARGET is used to help determine whether a postback event has occurred. The Page.IsPostBack property is set when the Page.DeterminePostBackMode method is called.