instead of doing
session(\"myvar1\") = something
session(\"myvar2\") = something
session(\"myvar3\") = something
session(\"myvar4\") = something
I came up with a solution that avoids certain disadvantages of the other solutions posted by keeping the structure of the Session variables intact. It is simply a type-safe shortcut to get and set Session variables.
It's C#, but I posted some auto-generated VB.NET at the end.
The best solutions I have seen (the accepted answer and the one by TheObjectGuy) require a custom class that is stored in a Session variable, and then is pulled from the Session to access its properties with something like MySessionClass.Current.MyProperty.
The problem with this is that if you are currently using (or may use in the future) something other than an InProc Session-State mode (see https://msdn.microsoft.com/en-us/library/ms178586%28v=vs.140%29.aspx), the whole class would have to go through serialization to access a single property.
Also, that means you lose the IEnumerable and ICollection implementations offered by the actual Session, if you need those. With my solution, you can simply access the actual Session if you need this functionality.
You can easily use these session variables and they are type-safe. It can be used alongside statements like Session["MyProperty"], which will allow for conversion of an existing project one reference at a time. So:
int myInt = (int)Session["MyInt"];
Session["MyInt"] = 3;
becomes:
int myInt = SessionVars.MyInt;
SessionVars.MyInt = 3;
Here is the actual class. The CallerMemberName requires .NET 4.5, but even if you are using an older version you could still manage it by explicitly passing the propertyName. Also, the types of the properties must be nullable to make it act exactly the same as standard Session["MyProp"] calls because a non-set
public static class SessionVars
{
private static T Get2<T>([System.Runtime.CompilerServices.CallerMemberName] string propertyName = "")
{
if (HttpContext.Current.Session[propertyName] == null)
{
return default(T);
}
return (T)HttpContext.Current.Session[propertyName];
}
private static void Set2<T>(T value, [System.Runtime.CompilerServices.CallerMemberName] string propertyName = "")
{
HttpContext.Current.Session[propertyName] = value;
}
public static int MyInt { get { return Get2<int>(); } set { Set2<int>(value); } }
public static bool MyBool { get { return Get2<bool>(); } set { Set2<bool>(value); } }
public static string MyString { get { return Get2<string>(); } set { Set2<string>(value); } }
}
I even wrote a code snippet to facilitate adding these properties:
<?xml version="1.0" encoding="utf-8"?>
<CodeSnippet Format="1.0.0" xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">
<Header>
<Title>SessionVars Property</Title>
<Author>kevinpo</Author>
<Shortcut>sv</Shortcut>
<Description>Adds a property for use in a SessionVars class</Description>
<SnippetTypes>
<SnippetType>Expansion</SnippetType>
</SnippetTypes>
</Header>
<Snippet>
<Declarations>
<Literal>
<ID>type</ID>
<Default>int</Default>
</Literal>
<Literal>
<ID>property</ID>
<Default>PropertyName</Default>
</Literal>
</Declarations>
<Code Language="CSharp">
<![CDATA[public static $type$ $property$ { get { return Get2<$type$>(); } set { Set2<$type$>(value); } }]]>
</Code>
</Snippet>
</CodeSnippet>
I'm a C# guy, so this VB.NET is just auto-converted by http://converter.telerik.com/:
Public NotInheritable Class SessionVars
Private Sub New()
End Sub
Private Shared Function Get2(Of T)(<System.Runtime.CompilerServices.CallerMemberName> Optional propertyName As String = "") As T
If HttpContext.Current.Session(propertyName) Is Nothing Then
Return Nothing
End If
Return DirectCast(HttpContext.Current.Session(propertyName), T)
End Function
Private Shared Sub Set2(Of T)(value As T, <System.Runtime.CompilerServices.CallerMemberName> Optional propertyName As String = "")
HttpContext.Current.Session(propertyName) = value
End Sub
Public Shared Property MyInt() As Integer
Get
Return Get2(Of Integer)()
End Get
Set
Set2(Of Integer)(value)
End Set
End Property
Public Shared Property MyBool() As Boolean
Get
Return Get2(Of Boolean)()
End Get
Set
Set2(Of Boolean)(value)
End Set
End Property
Public Shared Property MyString() As String
Get
Return Get2(Of String)()
End Get
Set
Set2(Of String)(value)
End Set
End Property
End Class
'=======================================================
'Service provided by Telerik (www.telerik.com)
'Conversion powered by NRefactory.
'Twitter: @telerik
'Facebook: facebook.com/telerik
'=======================================================
How about:-
public static class SessionVar
{
public static readonly string myVar1 = "myVar1";
public static readonly string myVar2 = "myVar2";
public static readonly string myVar3 = "myVar3";
public static readonly string myVar4 = "myVar4";
}
This allows you to use:-
session(SessionVar.myVar1) = something;
I've used classes like this to make a typed session/cache wrapper. You may need to add additional code to the get/set, but I'll leave that up to you.
internal class SessionHelper
{
private const string myVar1Key = "myvar1";
public static int MyVar1
{
get
{
return (int)System.Web.HttpContext.Current.Session[myVar1Key];
}
set
{
System.Web.HttpContext.Current.Session[myVar1Key] = value;
}
}
}
Sorry about the C#....
Instead of using constants for the session keys, I'm using my own type-safe session object, which looks like this (sorry this is in C#, see below for a VB version):
public class MySession
{
// Private constructor (use MySession.Current to access the current instance).
private MySession() {}
// Gets the current session.
public static MySession Current
{
get
{
MySession session = HttpContext.Current.Session["__MySession__"] as MySession;
if (session == null)
{
session = new MySession();
HttpContext.Current.Session["__MySession__"] = session;
}
return session;
}
}
// My session data goes here:
public string MyString { get; set; };
public bool MyFlag { get; set; };
public int MyNumber { get; set; };
}
Whenever I need to read/write something to/from the session, I can use my typesafe session object like this:
string s = MySession.Current.MyString;
s = "new value";
MySession.Current.MyString = s;
This solution results in several advantages:
Update: Here's a VB version (automatically converted from the C# version). Sorry, but I don't know VB and so I didn't know how to write the properties in VB:
Public Class MySession
' Private constructor (use MySession.Current to access the current instance).
Private Sub New()
End Sub
' Gets the current session.
Public Shared ReadOnly Property Current() As MySession
Get
Dim session As MySession = TryCast(HttpContext.Current.Session("__MySession__"), MySession)
If session = Nothing Then
session = New MySession()
HttpContext.Current.Session("__MySession__") = session
End If
Return session
End Get
End Property
' My session data goes here:
Public MyString As String
Public MyFlag As Boolean
Public MyNumber As Integer
End Class
Only if those values are related. Otherwise use plain old constants.
I realize this question was asked a while ago and an "answer" has already been picked. But I just came across it. Martin's answer is good. However, to assist anyone who stumbles across this in the future, if you really want a slick way to deal with Session, read this post. I don't think you'll find anything easier.