This message sets the formatting rectangle for a control. The text is reformatted and redisplayed to reflect the changed rectangle. The EM_SETRECTNP message is the same as the EM_SETRECT message, except that the control is not repainted. Any subsequent alterations cause the control to be repainted to reflect the changed formatting rectangle. This message is used when the field is to be repainted later.
| Parameter | Description |
| wParam | Is not used. | |
| lParam | Points to a RECT data structure that specifies the new dimensions of the rectangle. |
This message will not be processed by single-line edit controls.