What is the difference between ASP.NET 4 and ASP.NET 3.5?

ASP.NET 4 is the latest version of ASP.NET and ASP.NET 3.5 is the major ASP.NET version that is released prior to ASP.NET 4. ASP.NET 3.5 was released on November 2007 and ASP.NET 4.0 was released on April 2010. The major differences between ASP.NET 4 and ASP.NET 3.5 are:  

ASP.NET 4

ASP.NET 3.5

In ASP.NET 4, the data from the client side can be directly accessed using client data view and client data context objects.

In ASP.NET 3.5, the data from the client side cannot be directly accessed. The client side data can only be accessed using script manager’s Page methods, interface named ICallbackEventHandler or by using the component XMLHttpHandler.

The meta keywords and meta description is really useful for SEO optimization of the web page. In ASP.NET 4, the keywords and description can be included as part of page directive itself. For instance,

<%@ Page …..

Keywords= “keyword_1, keyword_2”

Description=“description_1, description_2” %>

 

In ASP.NET 3.5, two meta tags can be used, one with name as keywords and other with name as description to record the keywords and description for SEO purpose.

 

 

 

In ASP.NET 4, the acceptable values of ViewStateMode property are Enabled, Inherit and Disabled. 

In ASP.NET 4, the acceptable values of ViewStateMode property are true and false.

In ASP.NET 4, a property called ClientIDMode is newly introduced to identify and record the ClientId easily.

In ASP.NET 3.5, ClientId property has to be used to find the dynamically generated client id.