When a form is displayed modally, no input (keyboard or mouse click) can occur except to objects on the modal form. The program must hide or close a modal form (usually in response to some user action) before input to another form can occur. Forms that are displayed modally are typically used as dialog boxes in an application.

You can use this property to determine whether a form that you have obtained from a method or property has been displayed modally.

To display a form modally use the Form.ShowDialog method.