The SB_SETPARTS message sets the number of parts in a status window and the coordinate of the right edge of each part.
SB_SETPARTS
wParam = (WPARAM) nParts;
lParam = (LPARAM) (LPINT) aWidths;
Parameters
nParts
Number of parts to set. The number of parts cannot be greater than 255.
aWidths
Pointer to an integer array that has the same number of elements as parts specified by nParts. Each element in the array specifies the position, in client coordinates, of the right edge of the corresponding part. If an element is - 1, the position of the right edge for that part extends to the right edge of the window.
Return Values
If the operation succeeds, the return value is TRUE.
If the operation fails, the return value is FALSE.