EM_SETTARGETDEVICE  EF_BH9 

The EM_SETTARGETDEVICE message sets the target device and line width used for WYSIWYG (what you see is what you get) formatting in a rich edit control.

EM_SETTARGETDEVICE

wParam = (WPARAM) (HDC) hdcTarget;

lParam = (LPARAM) (int) cxLineWidth;

Parameters

hdcTarget

Handle to a device context for the target device.

cxLineWidth

Line width to use for formatting.

Return Values

Returns a nonzero value if successful or zero otherwise.