Variables don’t automatically maintain state across page calls in ASP.NET. Asp.Net Page has a life cycle and being stateless, the information is lost at the end of this cycle, after a request has been served on the client side. One way is to use View-state for the persistence of the variables, but this significantly increases the size of a page and the data sent and received, making it slow. There are several solution for this.
Here is SessionState example
// saving aHiddenVariable Session["aHiddenVariable"]="aHiddenVariable"; // retreiving aHiddenVariable string aHiddenVariable = (string)Session["aHiddenVariable"];
Here is hidden field example.
In HTML, we simply need to create:
<input type="hidden" id="aHiddenVariable">
document.getElementById("aHiddenVariable").value = "myValue"
In ASP.NET code-behind, you use the Request object to retrieve the value.
string aHiddenVariable= (string)Request.Params["aHiddenVariable"];
Here is a sample for QueryString
// setting quesryString // set s=feed, "text" to search http://codingphobia.com/?s=feed // retrieve variable string textToSearch= Request.QueryString["s"];