does Session.Clear(); clears all sessions data - asp.net-mvc

Question

I Want to clear one session Data but it's clearing both Sessions data. below is my 2 MVC action methods which are used to clear Session data.
1)
public int Clearsesson()
{
int i = 0;
List<Wish_Product> products = new List<Wish_Product>();
if (**Session["WishItem"]** != null)
{
Session.Clear();
i = 1;
}
else
{
i = 0;
}
return i;
}
2)
public int Clearsesson2()
{
int i = 0;
List<Cart_Product> products = new List<Cart_Product>();
if (**Session["CartItem"]** != null)
{
// Session.Remove("CartItem");
Session.Clear();
i = 1;
}
else
{
i = 0;
}
return i;
}
So like this I am storing Data in two Sessions but when I run this asp.net MVC Action method to clear One session data, it automatically clears second one Session Data too.
Why so like this? Please make it clear to me why it's happening.
Or what I've to do to solve this problem?

Answer 1

The short answer is yes, on the current collection.
According to ASP.NET documentation, HttpSessionState.Clear method removes all keys and values from currently active session state collection (it doesn't destroy user's session state base), so that both Session["WishItem"] & Session["CartItem"] values are cleared together from collection when the method is executed, but the session state base kept alive.
There are 2 different session collection keys in this case & actually both of them using same session state. To clear single session data, there are 2 different ways:
1) Remove session key using Session.Remove.
Session.Remove("WishItem");
2) Assign null value to the session state based with its key.
Session["WishItem"] = null;
The difference between them is that the former deletes both keys and values so that it won't appear as key-value pair in session collection anymore, and the latter overwrites current collection value with specified key but the key name still unchanged.
Therefore, you can remove each session data separately without clearing another session key like this:
public int ClearSession()
{
int i = 0;
// other code logic
if (Session["WishItem"] != null)
{
// only WishItem key has cleared
Session.Remove("WishItem");
i = 1;
}
// other code logic
}
public int ClearSession2()
{
int i = 0;
// other code logic
if (Session["CartItem"] != null)
{
// only CartItem key has cleared
Session.Remove("CartItem");
i = 1;
}
// other code logic
}
Note that each authenticated user always be assigned with one session state base, hence using Session.Clear removes all existing key-value pairs stored in session collection for current user (doesn't affect other user's session state).