How To Declare DLL files

[bebbo]

The code below is VB code declaring a dll file.

Private Declare Function IxCF Lib "CrystalFontz.dll" (ByVal pFunc As Long)

Private Declare Function TxCF Lib "CrystalFontz.dll" (ByVal strBuffer As String, ByVal lngSize As Long) As Long

Do I declare this in Foxpro as below:

DECLARE LONG lxCF IN CrystalFontz.DLL LONG @,
DECLARE LONG TxCF IN CrystalFontz.DLL STRING @, LONG @

If not how do I do it. Thanks

 

[craigsboyd]

Close, try this:

DECLARE LONG lxCF IN CrystalFontz.dll LONG
DECLARE LONG TxCF IN CrystalFontz.dll STRING, LONG

...if that doesn't work then try:

DECLARE INTEGER lxCF IN CrystalFontz.dll INTEGER
DECLARE INTEGER TxCF IN CrystalFontz.dll STRING, INTEGER


...you'll notice that I removed the "@" from your declarations, this is because according to the VB declarations the paramters are sent in ByVal. You would use the "@" symbol if the parameters were ByRef.

Slighthaze = NULL
_{craig1442@mchsi.com}

"Whom computers would destroy, they must first drive mad." - Anon​

 

[bebbo]

Thanks

In VB you can set Function Pointers to DLL Procedures and Type Libraries. Can you do this in VF?

VB example below

IngRet = TxCF(AddressOf CF_Callback)

Once again thanks.

 

[craigsboyd]

bebbo,

VFP has nothing that is equivalent to the AddressOf in VB. Callbacks in the sense in which you are referring to them are for all purposes non-existant in VFP.

Slighthaze = NULL
_{craig1442@mchsi.com}

"Whom computers would destroy, they must first drive mad." - Anon​

 

[bebbo]

If there is no equivalent of AddressOf how can I get information back from a Dll file.

I know I can do the following

result = open(par1,par2)

Therefore I get a setting set to result.

How do I then let the dll file send me other information. e.g 50p entered, another 50p entered, £1 entered etc...

 

[AirCon]

bebbo,

If there is no equivalent of AddressOf how can I get information back from a Dll file

The only way is to create your own wrapper. If you want to try, here is one "VFP Callback wrapper". I don't know if it is working perfectly because I never use it myself.

http://www.universalthread.com/wconnect/wc.dll?FournierTransformation~2,54,1,5

Search for ID: 20453


-- AirCon --

 

[AirCon]

One more thing, that wrapper also contains the source code ( C# )

Regards

-- AirCon --