BCGControlBar Pro for MFC
void CBCGPEditCtrl::SetLineNumbersMargin ( BOOL  bShow = TRUE,
int  nMarginWidth = 45,
int  nExtraMarginWidth = 0 
)

Shows or hides line numbers.

Use this function to show or hide line numbers. The line numbers are displayed at the left side of each text line.

Parameters
bShowSpecifies whether the line number margin is visible (TRUE) or not (FALSE).
nMarginWidthSpecifies the width of the line number margin in pixels.
nExtraMarginWidthSpecifies the extra width of the line number margin in pixels.