Jump to content

LVCLASS File Extension

From LabVIEW Wiki
(Redirected from Class library)

The LabVIEW Class file extension (*.lvclass) is used for class libraries in LabVIEW object-oriented programming. A class library is a special form of project library that defines a new data type in LabVIEW. It contains meta data about the class and its members, a private custom control that is embedded in the class library (there is no separate file on disk) and links to class methods.

In LabVIEW 2025 Q1, the LabVIEW Class file no longer stores the connector panes of member VIs in binary format. Instead, LabVIEW stores a NI.ClassItem.InvokeUsage property that is a number:

  • 1 = Dynamic method
  • 2 = Static property read
  • 3 = Static property write
  • 4 = Dynamic property read
  • 5 = Dynamic property write
  • 6 = Data unflatten (loads the class to unflatten a piece of data)
  • 7 = Exists (loads the class for the private data control)
  • 8 is unused
  • 9 = Not a function (used for controls, globals or Polymorphic VIs)

See also