How to get readonly textbox value in codebehind or CS file

As we know that when we declare a textbox as readonly then we didnot get value from that readonly textbox from code file. Because asp.net rejects any changes in readonly textbox after postback. Here in this article i will describe ASP.NET Read Only TextBox lose client side changes, values across post back? Why Readonly Text box values are empty in code behind ? Issue in Retrieving textbox value