Monday, January 25, 2010

What is New in ASP.NET 4.0, Visual Studio 2010 IDE


This article is an introduction to some of the new features in ASP.NET 4.0 and Visual Studio 2010 IDE.

Code Snippets

Code snippets are pre-developed code templates which can save time spent on thinking about the syntax. There are already a lot of built-in code snippets in VS2005 and VS2008. However, those are only available for the code-behind. Code snippets in VS2010 are introduced for JScript, HTML, and ASP.NET markup as well. In the screenshots below, we can see different snippet context menus for JScript and HTML.
Inside the script tag, it would be

And inside the HTML:

New Profiles

We have seen different development profiles in previous versions of .NET. Like VB, C#, Web Development, and General Development. We select a profile based on our priorities. These are selected after the first installation of Visual Studio or from the Import Export option.

In VS2010, two more profiles are introduced and both support HTML developers. Those are:
  1. Web Development
  2. Web Development (Code Optimized)

The Web Development profile hides the client objects and events bar on top in HTML mode.

In Code Optimized, you will find the HTML editor without code, and the designer tabs. So, it provides a more bigger area on the screen to play with HTML.

You can choose a profile after installation of Visual Studio on first use. You can also change the existing working profile from the Tools > Import & Export Settings > Reset all settings option. You will have to open and close Visual Studio if it does not show the changes in the IDE.

Generate From Usage

In previous versions of ASP.NET, Microsoft introduced code refactoring to generate methods and identifiers from existing code. In ASP.NET 4.0, there is a new concept of Generate From Usage - generates properties, methods, classes, and other types based on existing code.
Write some code, select it and right click on the left most character, and you will get options to change it to a property or method etc. This option is shown only if you do not define an identifier. For example, in the following example intellisense, it will not show the options to extract a property if you right click on the variable i.


In VS2008, it is possible to create a project in version 2.0 or 3.0, rather than developing in default 3.5. Also, there is an option to change a developed project's target framework version.
The same option is available in VS2010, but with one improvement. In the previous versions, if you create a project in framework 2.0, intellisense will still show you the types and members of 3.5 version as well, so there are more chances of error if you cannot identify the member of the chosen framework. But in VS2010, the intellisense will show you options for the appropriate framework only.


Visual Studio 2010 provides us facility to move windows of the IDE outside of the Visual Studio IDE and place them on the desktop area. It also supports having different IDE windows on multiple monitors. If we close Visual Studio and open it again, we will find all the windows on the same places where we finished them last time.

Code Navigation in Class Files

Code Navigation

A new Navigate To option gives us facility to search a term in a file more quickly. It searches the text as you type, but it works for class files only, i.e., it doesn't work for HTML or code-behind files. In the following example, it shows the function name as I type it in the Navigate To window; on selection of any, it will navigate to the function definition.

See full details: