How can I get the value of a session variable inside a static method?
I am using ASP.NET page methods with jQuery.... How do I get the value of a session variable inside a static method in C#?
protected void Page_Load(object sender, EventArgs e)
{
Session["UserName"] = "Pandiya";
}
[WebMethod]
public static string GetName(开发者_开发问答)
{
string s = Session["UserName"].ToString();
return s;
}
When I compile this I get the error:
An object reference is required for the non-static field, method, or property 'System.Web.UI.Page.Session.get'`
HttpContext.Current.Session["..."]
HttpContext.Current
gets you the current ... well, Http Context; from which you can access: Session, Request, Response etc
If you haven't changed thread, you can use HttpContext.Current.Session
, as indicated by jwwishart.
HttpContext.Current
returns the context associated with the thread. Obviously this means you can't use it if you've started a new thread, for example. You may also need to consider thread agility - ASP.NET requests don't always execute on the same thread for the whole of the request. I believe that the context is propagated appropriately, but it's something to bear in mind.
Try this:
HttpContext.Current.Session["UserName"].ToString();
You can access the current Session
via HttpContext.Current
- a static property through which you can retrieve the HttpContext
instance that applies to the current web request. This is a common pattern in static App Code and static page methods.
string s = (string)HttpContext.Current.Session["UserName"];
The same technique is used to access the Session
from within ASMX web methods decorated with [WebMethod(EnableSession = true)]
because whilst such methods are not static they do not inherit from Page
and thus do not have direct access to a Session
property.
Static code can access the Application Cache in the same way:
string var1 = (string)HttpContext.Current.Cache["Var1"];
If the static code is inside another project we need to reference System.Web.dll
. However, in this case it is generally best to avoid such a dependency because if the code is called from outside of an ASP.NET context HttpContext.Current
will be null
, for obvious reasons. Instead, we can require a HttpSessionState
as an argument (we'll still need the reference to System.Web
of course):
public static class SomeLibraryClass
{
public static string SomeLibraryFunction(HttpSessionState session)
{
...
}
}
Call:
[WebMethod]
public static string GetName()
{
return SomeLibraryClass.SomeLibraryFunction(HttpContext.Current.Session);
}
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