Overview of User-Defined Functions in C
The Crystal Reports Formula Editor and formula language are powerful tools, enabling you to perform a wide variety of report-related tasks easily and efficiently. The formula language is expandable as well. That is, while it already includes a large selection of useful functions, it also comes with the ability to accept new functions that you define to meet your needs.
User-Defined Functions that are recognized by the Crystal Reports Formula Editor can be created in a Dynamic Link Library or, for 32-bit environments, in an Automation Server. This section demonstrates how to create User-Defined Functions in a Dynamic Link Library using the C programming language. For information on how to create User-Defined Functions in an Automation Server using Visual Basic or Delphi, see Creating User-Defined Functions in Visual Basic or Creating User-Defined Functions in Delphi 3.0.