Ajaxpro session usage notes

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• Solution:

Ajaxpro session usage error (ajaxpro "session" causes an exception of the "system. nullreferenceexception" type)

For more information about how to use ajaxpro in ASP. NET, see Code : [Ajaxpro. ajaxmethod (ajaxpro. httpsessionstaterequirement. readwrite)]
Public   String Btnnextzx ( String Data)
{

Stringbuilder zx_ret =   New Stringbuilder ();
Hashtable hash = (Hashtable) session [ " Jgd_data " ];

Note: The error caused by the absence of ["jgd_data"] in the session is excluded here. Of course, the following error is not reported even if it does not exist:

Strange! I have added the following code !![Ajaxpro. ajaxmethod (ajaxpro. httpsessionstaterequirement. readwrite)]

Solution:

Run the following code:Hashtable hash=(Hashtable) session ["Jgd_data"];

Replace it with the following code:Hashtable hash=(Hashtable) httpcontext. Current. session ["Jgd_data"];

Execute OK !!

Find the cause: the session, application, request, and so on are inherited by the page class (you can this. when using ajax.net to access background methods, these methods do not belong to the page class, so they need to be accessed from httpcontext. read in current. The session is more special. You need to add [ajaxpro. ajaxmethod (ajaxpro. httpsessionstaterequirement. readwrite)] to be accessed.