[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'Forms' (#lcl)

# TCustomForm.OnWindowStateChange

Handler called when the form is minimized, maximized or restored.

## Declaration

Source position: forms.pp line 813

`public property TCustomForm.OnWindowStateChange : TNotifyEvent read FOnWindowStateChange write FOnWindowStateChange;`

## Description

OnWindowStateChange is a TNotifyEvent property which represents the event handler signalled when the value for the WindowState property is changed. OnWindowStateChange is triggered (when assigned) from the Resizing method, and occurs when the WM_SIZE window message for the action is handled.

See TWindowState for details about the values and meanings in the enumeration.

## See also

TCustomForm.WindowState |  | Indicates whether the form is displayed in a minimized, maximized, full-screen or normal state.
TCustomForm.Resizing |  | Performs actions needed when the form processes the WMSize message.
TCustomForm.WMSize |  | Handles the LM_SIZE window message for the form.
TWindowState |  | Represents the actual State of the window on the screen.