.Net framework is now a day creating a big hike in the market. A person can able to make any kind of application using .Net framework. And one of such application is for the smart devices. The .NET Compact Framework is used to develop applications for smart devices. By smart devices we mean devices that run the Pocket PC 2000, Pocket PC 2002 and Windows CE.NET operating systems. These operating systems are targeted for mobile devices (like PDA, Pocket PC) that have small display areas, small storage areas and run on batteries.

Developing applications for devices has never been easier! Earlier, people had to grapple with the eMbedded Visual Tools kit from Microsoft. This toolkit essentially consists of an operating system and development tools (like embedded Visual Basic and embedded Visual C++). Application also had to deal with different programming models and understand and work with the API of the operating system. With the advent of the .NET Compact Framework, Microsoft has unified the programming models between developing applications for PC's and applications for devices. The
.NET Compact Framework provides a managed execution environment for applications on devices and makes writing applications extremely easy.

Introduction to .NET Compact Framework

The .NET Compact Framework is a subset of the functionality found in the .NET Framework. Major portions of the .NET Framework were removed, since these did not make sense in the devices world. When we say removed, it does not mean that the code was simply cut-off and the remaining code got renamed as Compact Framework :-) Microsoft re-wrote large chunks of the code to take into account the form factor of small devices.

Common Language Runtime

The CLR is the most important part of the .NET Compact Framework. It is responsible for taking a .NET assembly and then setting up an application domain for it to run. A native just-in-time (JIT) compiler is used to compile the MSIL code to the actual machine bits. The CLR provides the services of memory management, garbage collection and class loading. The CLR also manages the security structure in which the application executes.

The CLR consists of two parts. One is the direct execution engine which is responsible for execution of the code and the other is the base class libraries which is a set of reusable classes that contain a basic set of building blocks that applications can use. The following figure shows a typical construction of the .NET Compact Framework.

The diagram is pretty straight forward.

• Applications, device libraries and base class libraries occupy the managed space. The CLR provides the execution environment for these applications along with a set of base services.  
  

• The execution engine itself is a native executable, as is the Platform Adaptation Layer which is an abstraction between the execution engine and the underlying operating system.

These two layers are packaged as a single executable called MSCOREE.

In the .NET Compact Framework, there is one implementation of the MSCOREE for each of the supported processors. If future platforms become available with more capabilities, it is only the PAL that needs to be changed, since it contains platform specific features that will change between each hardware.

Features Missing From .NET Compact Framework

As mentioned earlier, the .NET Compact Framework is a subset of the full .NET Framework and major sections were ignored because they implemented features that were specific to the PC platform, which did not make sense in the device world. The following is a brief summary of the features that are excluded from the .NET Compact Framework.

• No application configuration files.

• No support for COM Interop.

• No support for remoting.

• No support for printing.

• No support for the SoapFormatter or the BinaryFormatter classes.

• No support for XPath and XSLT.

• No support for the System.Web namespace.

Availability of .NET Compact Framework

Visual Studio .NET includes all the capabilities that allow you to write and debug a device application (called Smart Device Extensions). You use all the tools and techniques that are available for developing normal application when writing device applications too. Instead of using the .NET Framework class libraries, you use the Compact Framework specific libraries.

Conclusion

In this article we have seen what exactly the .NET Compact Framework is and where it is used. To develop a simple application and how to deploy the application onto the device one has to work on VS studio .NET. The Visual Studio .NET development environment provides a very productive IDE for developing smart-device applications and also provides excellent emulation and debugging support. There are many different types of applications that you can write using the .NET Compact Framework and this hopefully helped you make a good start to work with .NET compact framework.