Adding External DLL Calls

[Jeff Barnes]

Hi Everybody,

I have looked at many posts and am trying to add external DLL calls to my app.

Can someone please tell me where I am going wrong.


Syntax :
Function Connect() as String
Return values:
Success - Port number
Error - Empty String

DLL32 FUNCTION Connect() AS LPSTR PASCAL LIB "\Ez\dll\POx.DLL"



Syntax :
Function Handshake() as Boolean
Return values:
Success - TRUE
Error - FALSE

DLL32 FUNCTION Handshake() AS BOOL PASCAL LIB "\Ez\dll\POx.DLL"



Syntax :
Function SetID(id as String) as Boolean
Return values:
Success - TRUE
Error - FALSE

DLL32 FUNCTION SetID(ID AS LPSTR) AS WORD PASCAL LIB "\Ez\dll\POx.DLL"



Syntax :
Function SetTime( cur_time as Date) as Boolean
Return values:
Success - TRUE
Error - FALSE

DLL32 FUNCTION SetTime(cur_time AS Date) AS WORD PASCAL LIB "\Ez\dll\POx.DLL"



Syntax :
Function SetInterval(interval as Integer) as Boolean
Return values:
Success - TRUE
Error - FALSE

DLL32 FUNCTION SetInterval(interval AS LONG) AS WORD PASCAL LIB "\Ez\dll\POx.DLL"


Syntax :
Function GetData(data_array()) as integer
Return values:
Success - Number of Data lines
Error - 0

DLL32 FUNCTION GetData(data_array()) AS LONG PASCAL LIB "\Ez\dll\POx.DLL"

Thanks,
Jeff

[James Bott]

Jeff,

Try it this way:

Code: Select all | Expand

local hPOX := LoadLibrary( "\ez\dll\POX.DLL" )

DLL32 FUNCTION ... LIB hPOX

...

FreeLibrary( hPOX )

James

[Jeff Barnes]

Hi James,

When I try it that way and issue the Connect() command I get the following error:

Unrecoverable error 9003:
Too many recursive error handler calls

[James Bott]

Jeff,

I'm not experienced with DLL32 calls, but I notice other working calls (in my notes) use the FROM clause and the same name as the function with a trailing "A" so you might try:

DLL32 FUNCTION Connect ... FROM "ConnectA" LIB hPOX

If that doesn't work, hopefully someone else with DLL experience will help.

James

[Jeff Barnes]

Thanks for trying James ... Still no luck.

[Enrico Maria Giordano]

Syntax :
Function Connect() as String
Return values:
Success - Port number
Error - Empty String

DLL32 FUNCTION Connect() AS LPSTR PASCAL LIB "\Ez\dll\POx.DLL"

As far as I know, you can't return a string from a DLL function. Do you have any VB samples?

Syntax :
Function SetID(id as String) as Boolean
Return values:
Success - TRUE
Error - FALSE

DLL32 FUNCTION SetID(ID AS LPSTR) AS WORD PASCAL LIB "\Ez\dll\POx.DLL"

AS BOOL instead of AS WORD.

DLL32 FUNCTION SetTime(cur_time AS Date) AS WORD PASCAL LIB "\Ez\dll\POx.DLL"

There's nothing like AS Date.

DLL32 FUNCTION GetData(data_array()) AS LONG PASCAL LIB "\Ez\dll\POx.DLL"

There's nothing like data_array() without data type.

EMG

[Jeff Barnes]

Hi Enrico,

Please check your email.


Thanks,
Jeff

[vilian]

Good Morning Enrico,
Have you ever had success to use these functions with DATE parameters?

[Enrico Maria Giordano]

No, you can't. You have to write a wrapper.