As already mentioned the Save and Load functions open and close the specified file, checking existance and requesting a file number so we can handle the data. This functions won't change later so you can use them in any other class you like!
Public Function SaveData( iFileName as String ) as Boolean
On Error GoTo 1
Dim FileNumber as Integer
'Open the specified file
FileNumber = FreeFile
Open iFileName For Binary as FileNumber
'Write data
WriteData FileNumber
Close FileNumber
'We're done
SaveData = True
Exit Function
1 'Catched an error
SaveData = False
End Function
Not much to explain here... the function gets a file handle (FileNumber), opens the file and forwards the handle to the WriteData function. If everything works right the return value is True.
Public Function LoadData( iFileName as String ) as Boolean
On Error GoTo 1
Dim FileNumber as Integer
'Check existance
If Dir( iFileName, vbNormal ) = "" Then: GoTo 1
'Open the specified file
FileNumber = FreeFile
Open iFileName For Binary as FileNumber
'Read data
ReadData FileNumber
Close FileNumber
'We're done
LoadData = True
Exit Function
1 'Catched an error
LoadData = False
End Function
Nearly the same here, except that we check if the file exists before trying to open it.
As you can see both functions are quite general and don't name any module or class at all. However you still have to copy the code for any Module you need it.