Making a Text Buffer Read-only

For each edit control, the system maintains a read-only flag that indicates whether the control's text is read-write (the default) or read-only. An application can set the read-write or read-only flag for the text by sending the control an EM_SETREADONLY message. To determine whether an edit control is read-only, an application can call the GetWindowLong function using the GWL_STYLE constant. The EM_SETREADONLY message applies to both single-line and multiline edit controls.