The DateTimePicker.DropDown event occurs when the drop-down calendar is shown.

Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.

The DateTimePicker.OnDropDown(EventArgs) method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0