Being able to use .NET from C/AL code has been planned for a long time - the whole NAV Server architecture released with NAV 2009 has been building to this time where we can finally reach out from the NAV C/AL context and make use of these functions. The feature is very much part of our roadmap going forward where we want to give developers more power and allow partners to create solutions with much broader reaches than can be achieved within a native C/AL environment.

Referencing an external component will be similar to the pattern that Automation developers are accustomed to - you can quickly choose a component from the variable declaration window and then start using the object in C/AL with full support from NAV's Symbol Menu (F5). 

When working with variables of type DotNet, we distinguish between two sorts: Add-ins and those registered from the Global Assembly Cache (GAC). The Add-in type are those that are custom made or custom written, they do not need to be strong-named, and they may also change or are updated often. These components must be copied into a new directory (the Add-ins directory) on the developer's C/SIDE installation in order to be utilized. Variables based on types registered in the GAC are less likely to be swapped around but support strong-named types and include components like the .NET Framework. .NET Framework components have the additional benefit that they are already deployed on computers so there is no need for additional deployment!

Rather than elaborate more on the properties and definitions, let's look at a sample. In this code sample, we will use methods from the .NET Framework to retrieve a list of processes running on the NAV Server and show the process IDs in a message box. The sample is not exactly an ERP task but shows what can now be achieved by using .NET and hopes to show that familiar code patterns can be applied.

This screenshot shows the whole solution:

Notice that we have declared two DotNet variables here - myproclist, which is a System.Array and holds our list of processes, and process, which is a System.Diagnotics.Process subtype. Both variables are from the .NET Framework and are thus registered in the system GAC and we don't need to worry about deploying them for when we run the code.

Notice also that unlike Automation (based on COM), you don't always need to CREATE the objects. In DotNet, objects need to have a constructor called when they are instance-based or they may be used directly if they are static. The GetProcesses method is a static method in .NET, as we can see in the information section in our ever-helpful Symbol Menu.

Notice also that the C/AL code is able to loop through the Array. Using arrays (be they NAV arrays or .NET System.Arrays) is such a common programming pattern that it would be very wrong of us to not include it.

Of course using .NET is only supported on the NAV Server and, like Automation, you can also run the .NET objects either on the NAV Server or on the RoleTailored client.

Using .NET in C/AL will open many new options - more than we can possibly imagine. We hope you'll enjoy using this feature from NAV 2009 R2 and go on to make some fantastic new solutions for all our customers!

Good luck and happy coding!

source\fonte

http://blogs.msdn.com/b/nav/