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OnDropDown Method

ComboBox.OnDropDown Method

Raises the DropDown event.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

abstract OnDropDown : 
        e:EventArgs -> unit  
override OnDropDown : 
        e:EventArgs -> unit

Parameters

e
Type: System.EventArgs

An EventArgs that contains the event data.

This event is raised each time the drop-down is displayed.

Raising an event invokes the event handler through a delegate. For more information, see Handling and Raising Events.

The OnDropDown 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.

Notes to Inheritors

When overriding OnDropDown in a derived class, be sure to call the base class's OnDropDown method so that registered delegates receive the event.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
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