First, ensure a license is activated (see License Activation).
For projects targeting .NET Framework 4.5-4.8.1 (using the .NET 4.5 Framework assembly), users can choose between the newer .NET Standard Licensing technique (see .NET Standard Runtime Licensing) or the legacy .licx technique described here.
A licenses.licx file is required in the top-level executing assembly’s project, containing an entry for each licensed class (only one is necessary for each Dart assembly). When a licensed component is added to a project using the Visual Studio designer, a licenses.licx file is automatically generated if one does not already exist, and an entry for the class is added.
When developing an assembly with no design surface such as a console application, or when instantiating a licensed class in code, the licenses.licx file must be added manually. If a licenses.licx file is not present in the project, add a new text file named "licenses.licx" to the project (not the solution) from the Solution Explorer. Add a single line to the licenses.licx that includes the fully-specified class name and the assembly name, separated by a comma. For example:
Dart.Sockets.Tcp, Dart.Sockets
or
Dart.Sockets.Udp, %%AssemblyName%
The license compiler, lc.exe, will then create a licenses resource and embed it into the compiled application where it is validated at runtime.
Web Site projects include an App_Licenses.dll that must be rebuilt when changes are made to the licenses.licx file or when migrating from trial to licensed operation. The App_Licenses.dll can be rebuilt by right-clicking on the licenses.licx file in the Solution Explorer and selecting the "Rebuild Runtime Licenses" option.
If a library using a Dart component is developed for use in another top-level, executing assembly project, then that top-level project must include the licenses.licx file. If embedding a license resource in the consuming application is not possible then an Extended Distribution Product Key is required.