This code specifies that the user has taken an action that may have altered text. It is sent after Windows updates a display (unlike the EN_UPDATE code). The control's parent window receives this code through a WM_COMMAND message from the control.
| Parameter | Description |
| wParam | Contains the wParam parameter of the WM_COMMAND message, and specifies the control ID. | |
| lParam | Contains an edit-control window handle in its low-order word and the EN_CHANGE code in its high-order word. |