TBM_SETLINESIZE  M6TZ_P 

The TBM_SETLINESIZE message sets the size of the line for a trackbar. The line size affects how much the slider moves for the TB_LINEUP and TB_LINEDOWN notification messages.

TBM_SETLINESIZE
wParam = 0;

lParam = (LONG) lLineSize;

Parameters

lLineSize

New line size.

Return Values

Returns a 32-bit value that specifies the previous line size.