In ASP.NET, if you try to use a session or request variable before it has been set, you'll get an error. The following functions prevent this by checking for
nothing and returning a
null string if this is
true.
Public Shared Function zGetSessionValue
(ByVal se As HttpSessionState, ByVal keyItem As String) As String
'this proc avoids an error if the session variable has not been set
Dim res As String = ""
if se(keyItem) <> Nothing Then
res = se(keyItem)
End If
Return res
End Function
Public Shared Function zGetRequestValue
(ByVal re As HttpRequest, ByVal keyItem As String) As String
'this proc avoids an error if the request variable has not been set
Dim res As String = ""
If re(keyItem) <> Nothing Then
res = re(keyItem)
End If
Return res
End Function
'Usage --------------------------------------
Dim SVal as String
'if Session("MyVarName") has not been set SVal will be ""
SVal = zGetSessionValue(Session, "MyVarName")
Dim RVal as String
'if Request("MyVarName") has not been set RVal will be ""
RVal = zGetRequestValue(Request, "MyVarName")
