How to return a string from PROCEDUREDLL????

Sveinung · Post by **Sveinung** » Mon Nov 17, 2003 8:52 pm

How can I get the string value from my dll???

ProcedureDLL Read_String_DB(colum)
UseDatabase(1)
res.s=GetDatabaseString(colum)
ProcedureReturn res
EndProcedure

What the h*** am I doing wrong

Sveinung

Dreglor · Post by **Dreglor** » Mon Nov 17, 2003 9:04 pm

i not sure but try

ProcedureDLL.s Read_String_DB(colum)

GPI · Post by **GPI** » Mon Nov 17, 2003 9:50 pm

Better return a pointer to a global variable

global ReturnString.s

procedurereturn @ReturnString

Froggerprogger · Post by **Froggerprogger** » Tue Nov 18, 2003 2:04 pm

So use a procedure as (I think it's the same as GPI meant):

Code: Select all

ProcedureDLL Test()
  Global result.s
  result = "this is a string"
  ProcedureReturn @result
EndProcedure

and call it by

Code: Select all

OpenLibrary(0,"myDLL.dll")
procedureresult.s = PeekS(CallFunction(0,"Test"))
Debug procedureresult

You even might use an independant global variable named 'result' inside the main program.
You cannot use a protected variable inside the DLL because then it's value is pushed on the stack which gets 'cleaned' when leaving the procedure (though strings are handled slightly different). A CallFunctionS(tring) (and a CallFunctionF(loat)) would help here in future.

Sveinung · Post by **Sveinung** » Wed Nov 19, 2003 6:27 pm

Thank Froggerprogger!!!!

Worked fine!!!!

Sveinung

Sveinung · Post by **Sveinung** » Wed Nov 19, 2003 6:28 pm

AND GPI!!!!

Sveinung