BUG: CDK: VBSetVariantValue Return Value Changed in 4.0

RESOLUTION

To indicate success, change the DLL or VBX source code to handle return values of 0 or greater, instead of equivalence to 0. For example, if you have code that resembles the following:

   #include <vbapi.h>

   #define SUCCESS 0
   #define FAIL -1

   int VBAPI SetMyVariant (LPVAR pVariant)
   {
      short NewValue = 0x1234;
      ERR nResult;
      nResult = VBSetVariantValue (pVariant, VT_I2, (LPVOID) &NewValue);
      if (0 == nResult)
         return SUCCESS;
      else
         return FAIL;
   }
				

A DLL or VBX that contains this function correctly returns SUCCESS when used from a Visual Basic version 3.0 program. When the same DLL or VBX is used from a Visual Basic version 4.0 program, it incorrectly returns FAIL.

You can avoid this problem by changing the line:

   if (0 == nResult)
				

to

   if (0 <= nResult)
				

-OR-

you can test for a failure only. For example:

   if (-1 == nResult)
      return FAIL;
   else
      return SUCCESS;