The circular slider PM window class WC_CIRCULARSLIDER is similar to the window class of a linear slider or a scroll bar. This window class must be registered with WinRegisterCircularSlider before you can create a circular slider. A circular slider can be created by a CONTROL statement in a dialog resource, as shown in the following figure:
CONTROL "~Balance", ID_BALANCECS, 10, 50, 60, 60, WC_CIRCULARSLIDER, WS_TABSTOP | WS_VISIBLE | CSS_POINTSELECT
A circular slider also can be created by specifying the WC_CIRCULARSLIDER window class name as a parameter of the WinCreateWindow call, as shown in the following sample code:
hwndCS = WinCreateWindow (hwndClient, /* Parent handle */ WC_CIRCULARSLIDER, /* Class name */ "~Balance", /* Window text */ WS_VISIBLE | WS_TABSTOP | CSS_POINTSELECT, 0,0,0,0, /* Coordinates */ hwndClient, /* Owner handle */ HWND_TOP, /* Z-order */ ID_BALANCECS, /* Window ID */ NULL, /* Control data */ NULL); /* Presparam */