Querying control data
To
get at once all the data describing the current state of the
control via the SPLITCTLDATA structure you must use the
WM_QUERYWINDOWPARAMS PM message as described in the code snippet below.
WNDPARAMS wp;
SPLITCTLDATA scd;
memset(&scd, 0, sizeof(scd));
scd.cb = sizeof(scd);
memset(&wp, 0, sizeof(wp));
wp.fsStatus = WPM_CBCTLDATA | WPM_CTLDATA;
wp.cbCtlData = scd.cb;
wp.pCtlData = &scd;
if (WinSendMsg(g.hwndSplitPane, WM_QUERYWINDOWPARAMS, (MPARAM)&wp, MPVOID))
{
...
}