I have a structure like this
Subst As Boolean
nom As String
and then declare avariable for the structure:
Public LocalFitx() As PropsFitx
How can I know if I have initialized the variable?
The IsEmpty function returns me an error.
IsEmpty is used for variants which won't help you. What exactly are you trying to determine ? When you strongly type a variable, vb will automatically put a default - in your case, false for the boolean, and "" for the string.
In vb6 there is not an isnothing function. There is an isnothing function within vb.net which behaves like the "is nothing" test in vb6. However, both of these test whether an object has been instantiated.