HttpContext.Current.Request.UserHostName is empty when called from a class
I have various web pages that need to build up a URL to display or place it in an emitted email message. The code I inherited had this value for the name of the webserver in a Public Const in a Public Class called FixedConstants. For example:
Public Const cdServerName As String = "WEBSERVERNAME"
Trying to improve on this, I wrote this:
Public Class UIFunction
Public Shared myhttpcontext As HttpContext
Public Shared Function cdWebServer() As String
Dim s As New StringBuilder("http://")
Dim h As String
h = String.Empty
Try
h = Current.Request.ServerVariables("REMOTE_HOST").ToString()
Catch ex As Exception
Dim m As String
m = ex.Message.ToString() 'Ignore this should-not-occur thingy
End Try
If h = String.Empty Then
h = "SomeWebServer"
End If
s.Append(h)
s.Append("/")
Return s.ToString()
End Functi开发者_开发百科on
I've tried different things while debugging such as HttpContext.Current.Request.UserHostName and I always get an empty string which pumps out my default string "SomeWebServer".
I know Request.UserHostName or Request.ServerVariables("REMOTE_HOST") works when invoked from a page but why does this return empty when invoked from a called method of a class file (i.e. UIFunction.vb)?
I don't work with VB.NET, but if your class is compiled into another library, you can access the current page via (C#):
Page currentPage = System.Web.HttpContext.Current.Handler as Page;
string hostName = currentPage.Request.UserHostName;
And that should work. I use a similar method of adding validators dynamically for displaying messages to users.
As a starting point, you might want to check whether HttpContext.Current
is null
or not.
If this is null, you will get the same result as if you call HttpContext.Current.Request.ServerVariables("REMOTE_HOST")
(because of your try/catch)
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