MODAL vs MODELESS Forms

Question

What is the difference between MODAL and MODELESS Forms in Visual Basic ?

Vulpes · Answer

When you open a modal form (often called a dialog box) the code which follows it is not executed until the dialog box is closed. In contrast when you open a modeless form the code which follows it is executed immediately. In VB.NET forms are opened modally using the ShowDialog() method or modelessly using the Show() method. Another difference between the two is that a modal form can return a result (using the DialogResult property) which the following code can then take account of. Finally when you close a modal form using the X button (as opposed to programatically) the form is actually hidden rather than closed and can be shown again without creating a new instance. In this situation the DialogResult property is set to DialogResult.Cancel. Although in some ways this is convenient you have to remember to call Dispose when the modal form is no longer needed.