Conditional Compilation for Declare Statements

[tom.hogan]

I have several User Defined Types (UDT) of different DEVMODE structures that I would like to declare a variable with conditionally based on passing a variable argument to a function. My test code looks like:

Function TestConditionalCompile(DevModeType As Long) As Boolean

#If DevModeType = 1 Then
    Dim DM As DEVMODEPS500
#ElseIf DevModeType = 2 Then
    Dim DM As DEVMODEPS
#ElseIf DevModeType = 3 Then
    Dim DM As DEVMODEUNI500
#ElseIf DevModeType = 4 Then
    Dim DM As DEVMODEUNI
#Else
    Dim DM As DEVMODE
#End If
'execution code goes here
End Function

However, when I tested this code, no matter what DevModeType value I send to the function it always dimensions DM as the first UDT (DEVMODEPS500).

My question: Is it possible to dimension a variable conditionally based on a passed variable? If yes, how would I modify my code to achieve this?

Note: I cannot use the variant data type as it will not except a UDT.

Thanks,

Tom

[digitalShaman]

your code is mixing up conditional compilation based on compiler constants with function parameters which are only available and evaluated at run time.
what api are you dealing with? if you declare the parameter that will receive DM 'as any' you should be able to use a variant.

[tom.hogan]

I infer from your answer that you can only conditionally compile with constants (which is what I thought was true). Since I don't know which devmode structure I need until runtime this method will not work for me. To answer your question I am using CopyMemory (which requires a devmode structure) to set extended printer features. The required devmode changes with each printer. I can make it work with multiple select cases, but the conditional dim would have made it easier. Here is a snippet of the code FYI.

'code example of seting reverse print feature - it has to be duplicated for multiple features
Select Case lDevmodeType
  Case DEVMODE_BASIC
    Exit Sub  'Can't set reverse print in the basic devmode
  Case DEVMODE_UNIDRVEXTRA
    DMU.bReversePrint = 1
  Case DEVMODE_UNIDRVEXTRA500
    DMU.bReversePrint = 1
  Case DEVMODE_PSDRVEXTRA
    DMPS.bReversePrint = 1
  Case DEVMODE_PSDRVEXTRA500
    DMPS500.bReversePrint = 1
End Select

'after all printer features are set then write to proper devmode
Select Case lDevmodeType
   Case DEVMODE_BASIC
    Call CopyMemory(yDevmodeArr(1), DM, Len(DM))
  Case DEVMODE_UNIDRVEXTRA
    Call CopyMemory(yDevmodeArr(1), DMUNI, Len(DMUNI))
  Case DEVMODE_UNIDRVEXTRA500
    Call CopyMemory(yDevmodeArr(1), DMUNI500, Len(DMUNI500))
  Case DEVMODE_PSDRVEXTRA
    Call CopyMemory(yDevmodeArr(1), DMPS, Len(DMPS))
  Case DEVMODE_PSDRVEXTRA500
    Call CopyMemory(yDevmodeArr(1), DMPS500, Len(DMPS500))
End Select

Regards,

Tom

[tom.hogan]

I infer from your answer that you can only conditionally compile with constants (which is what I thought was true). Since I don't know which devmode structure I need until runtime this method will not work for me. To answer your question I am using CopyMemory (which requires a devmode structure) to set extended printer features. The required devmode changes with each printer. I can make it work with multiple select cases, but the conditional dim would have made it easier. Here is a snippet of the code FYI.

'code example of seting reverse print feature - it has to be duplicated for multiple features
Select Case lDevmodeType
  Case DEVMODE_BASIC
    Exit Sub  'Can't set reverse print in the basic devmode
  Case DEVMODE_UNIDRVEXTRA
    DMU.bReversePrint = 1
  Case DEVMODE_UNIDRVEXTRA500
    DMU.bReversePrint = 1
  Case DEVMODE_PSDRVEXTRA
    DMPS.bReversePrint = 1
  Case DEVMODE_PSDRVEXTRA500
    DMPS500.bReversePrint = 1
End Select

'after all printer features are set then write to proper devmode
Select Case lDevmodeType
   Case DEVMODE_BASIC
    Call CopyMemory(yDevmodeArr(1), DM, Len(DM))
  Case DEVMODE_UNIDRVEXTRA
    Call CopyMemory(yDevmodeArr(1), DMUNI, Len(DMUNI))
  Case DEVMODE_UNIDRVEXTRA500
    Call CopyMemory(yDevmodeArr(1), DMUNI500, Len(DMUNI500))
  Case DEVMODE_PSDRVEXTRA
    Call CopyMemory(yDevmodeArr(1), DMPS, Len(DMPS))
  Case DEVMODE_PSDRVEXTRA500
    Call CopyMemory(yDevmodeArr(1), DMPS500, Len(DMPS500))
End Select

Regards,

Tom