An application sends the EM_SETMARGINS message to set the widths of the left and right margins for an edit control. The message redraws the control to reflect the new margins.
EM_SETMARGINS
wParam = (WPARAM) fwMargin; // left and/or right margins
lParam = (LPARAM) MAKELONG(wLeft, wRight); // width of left or right margins, in pixels
Parameters
fwMargin
Value of wParam. Specifies the margins to set. This parameter can be a combination of the following values:
| Value | Meaning |
| EC_LEFTMARGIN | Sets the left margin. |
| EC_RIGHTMARGIN | Sets the right margin. |
| EC_USEFONTINFO | Uses information about the current font of the edit control to set the margins. For a single-line edit control, margins are set to the average width of characters in the font. For a multiline edit control, the right margin is set to the "A" width of the font (the distance added to the current position before drawing a character), and the left margin is set to the "C" width (the distance added to the current position to provide white space to the right of a character). |
If EC_USEFONTINFO is specified, the lParam parameter is ignored.
wLeft
Value of the low-order word of lParam. Specifies the width of the left margin, in pixels. This value is ignored if fwMargin does not include EC_LEFTMARGIN or if EC_USEFONTINFO is specified.
wRight
Value of the high-order word of lParam. Specifies the width of the right margin, in pixels. This value is ignored if fwMargin does not include EC_RIGHTMARGIN or if EC_USEFONTINFO is specified.
Return Values
This message does not return a value.
See Also