EM_SETZOOM message

Sets the zoom ratio for a multiline edit control or a rich edit control. The ratio must be a value between 1/64 and 64. The edit control needs to have the ES_EX_ZOOMABLE extended style set, for this message to have an effect, see Edit Control Extended Styles.

Parameters

wParam

Numerator of the zoom ratio.

lParam

Denominator of the zoom ratio. These parameters can have the following values.

Value Meaning
Both 0
Turns off zooming by using the EM_SETZOOM message (zooming may still occur using TxGetExtent).
1/64 < (wParam / lParam) < 64
Zooms display by the zoom ratio numerator/denominator

Return value

If the new zoom setting is accepted, the return value is TRUE.

If the new zoom setting is not accepted, the return value is FALSE.

Remarks

Edit: Supported in Windows 10 1809 and later. The edit control needs to have the ES_EX_ZOOMABLE extended style set, for this message to have an effect, see Edit Control Extended Styles. For information about the edit control, see Edit Controls.

Requirements

Minimum supported client
Windows Vista [desktop apps only]
Minimum supported server
Windows Server 2003 [desktop apps only]
Redistributable
Rich Edit 3.0
Header
Richedit.h/Commctrl.h

See also

EM_GETZOOM