Used to define conditional compiler constants for Visual Basic.
#Const constname = expression
Conditional compiler constants are always Private to the file in which they appear. You cannot create Public compiler constants using the #Const directive. Public compiler constants can only be created in the user interface.
Only conditional compiler constants and literals can be used in expression. Using a standard constant defined with Const will cause an error. Conversely, constants defined using the #Const keyword can only be used for conditional compilation. Constants can also be undefined, in which case they have a value of Nothing.
#If...Then...#Else Directive | Compiler Constants | Const Statement | Understanding Conditional Compilation | Using Constants | Using If...Then...Else Statements