The ReuseDDElParam function allows an application to reuse a packed DDE lParam parameter, rather than allocating a new packed lParam. Using this function reduces reallocations for applications that pass packed DDE messages.
LONG ReuseDDElParam(
| LONG lParam, | // posted lParam to be reused |
| UINT msgIn, | // identifier of received message |
| UINT msgOut, | // identifier of posted message |
| UINT uiLo, | // low-order word of new lParam |
| UINT uiHi | // high-order word of new lParam |
| ); |
Parameters
lParam
Specifies the lParam parameter of the posted DDE message being reused.
msgIn
Specifies the identifier of the received DDE message.
msgOut
Specifies the identifier of the DDE message to be posted. The DDE message will reuse the packed lParam parameter.
uiLo
Specifies the value to be packed into the low-order word of the reused lParam parameter.
uiHi
Specifies the value to be packed into the high-order word of the reused lParam parameter.
Return Values
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero.
Remarks
The return value must be posted as the lParam parameter of a DDE message; it must not be used for any other purpose. Once the return value is posted, the posting application need not perform any action to dispose of the lParam parameter.
Use ReuseDDElParam instead of FreeDDElParam if the lParam parameter will be reused in a responding message. ReuseDDElParam returns the lParam appropriate for reuse.
This function allocates or frees lParam parameters as needed, depending on the packing requirements of the incoming and outgoing messages. This reduces reallocations in passing DDE messages.
See Also