IXcallBlock Interface
The IXcallBlock interface is the interface passed to a Visual Basic or other COM based XCALL routine when an XCALL subroutine is called. It is the main interface through which the XCALL parameters can be accessed and set.
There are a number of functions, properties and methods for accessing XCALL arguments. The ArgValue property is the most flexible, but as it sets and returns a Variant as its value, performance will be very slightly slower than that of type-specific argument ‘Get’ and ‘Set’ routines. This will not be a concern unless the XCALL routine is called many thousands of times per second and absolute performance is required.
