Changes the amount of memory allocated to the memory block handle hand.


unsigned short _SetHandSize(MHANDLE hand, unsigned long size) MHANDLE hand; /* Memory block handle. / unsigned int size; / New number of bytes. */

Remarks

_SetHandSize( ) returns True (an integer other than 0) if the reallocation is successful, or False (0) if the reallocation fails. The data associated with the MHANDLE is preserved. If hand is a locked MHANDLE, _SetHandSize( ) fails.

For more information on how to create an API library and integrate it with Visual FoxPro, see Accessing the Visual FoxPro API.

Example

The following example uses _SetHandSize( ) to change the amount of memory allocated to an MHANDLE.

Visual FoxPro Code

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SET LIBRARY TO SETHANDS = HANDTOPTR("Hello, world.") && displays "Hello, world" on screen

C Code

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#include <pro_ext.h> void NullTerminate(Value FAR cVal) { if (!_SetHandSize(cVal->ev_handle, cVal->ev_length + 1)) { _Error(182); // "Insufficient memory" } ((char FAR ) _HandToPtr(cVal->ev_handle))[cVal->ev_length] = '\0'; } FAR Example(ParamBlk FAR parm) { NullTerminate(&parm->p[0].val); _HLock(parm->p[0].val.ev_handle); _PutStr(_HandToPtr(parm->p[0].val.ev_handle)); _HUnLock(parm->p[0].val.ev_handle); } FoxInfo myFoxInfo[] = { {"HANDTOPTR", (FPFI) Example, 1, "C"}, }; FoxTable _FoxTable = { (FoxTable FAR ) 0, sizeof(myFoxInfo)/sizeof(FoxInfo), myFoxInfo };

Copy Code

#include <pro_ext.h>
void NullTerminate(Value FAR *cVal)
{
   if (!_SetHandSize(cVal->ev_handle, cVal->ev_length + 1))
   {
      _Error(182); // "Insufficient memory"
   }
   ((char FAR *) _HandToPtr(cVal->ev_handle))[cVal->ev_length] = '\0';
}
FAR Example(ParamBlk FAR *parm)
{
   NullTerminate(&parm->p[0].val);
   _HLock(parm->p[0].val.ev_handle);
   _PutStr(_HandToPtr(parm->p[0].val.ev_handle));
   _HUnLock(parm->p[0].val.ev_handle);
}
FoxInfo myFoxInfo[] = {
   {"HANDTOPTR", (FPFI) Example, 1, "C"},
};
FoxTable _FoxTable = {
   (FoxTable FAR *) 0, sizeof(myFoxInfo)/sizeof(FoxInfo), myFoxInfo
};

Remarks

Example

Visual FoxPro Code

C Code

See Also

Reference

Other Resources