Call .Net class method in X++ code

You need to create .Net Class Library project if you want to consumen .Net functionality in you X++ project 

then On X++ class define .Net namespace like this

using KAFileFormatting;

then If you method is statis then you can call it like this 

KAFileFormatting.KATest::excelToPDF(memoryStream);

Here KAFileFormatting is the Namespace name of .Net project , KATest is the Class name and excelToPDF is the method name . Method can take multiple parameters.

Note: For Class library project your framework should be less than or equal to the framework of your X++ project. otherwise system cannot identify your namespace of .Net in X++ class.