Solution to fail to get the value of context. Session [& quot; xxx & quot;] On the ashx page

1-In aspx and aspx. cs, both are read and write based on Session ["xxx"] = "aaa" and aaa = Session ["xxx"]. ToString. In ashx, sessions use context. session. The read/write method is as follows: context. session ["xxx"] = "aaa" and aaa = context. session ["xxx"]. toString () 2-in the ashx file, to successfully read and write sessions, you should add the IRequiresSessionState interface after using the Session class (You may be prompted to add the namespace using System. web. sessionState reference), otherwise context. session ["xxx"] always reads null aspx. cs directly requests and sessions, while ashx is context. request and context. session. Aspx. cs can be used directly because of Web. UI. In ashx, Request and Session operations can only be performed on the HttpContext instance passed in. The cs file in the AppCode does not contain Web. UI and does not have the HttpContext parameter. If the current HttpContext can be obtained in cs, you can operate the Request and Session based on the HttpContext. To operate sessions in cs, the IRequiresSessionState interface should be added. The HttpContext class has a static property called Current. You can use this property to obtain the Current HttpContext. To obtain the IP address of the Current visitor in the cs file of AppCode, you can use HttpContext. Current. Request. UserHostAddress.