A comparison between session and ViewState

Session| Comparison session ViewState
Seize server resource true false
Time Out true False
Store any. NET type true false (only strings, integers, booleans, arrays, ArrayList, Hashtable, custom typeconverters) are supported
Increase HTML Load false true

The session is valid for the entire application, while the ViewState is equivalent
Session of a page

Define ViewState

Save in ViewState
viewstate["SortOrder"] = "DESC";

Read from ViewState
String sortOrder = (string) viewstate["SortOrder"];