This documentation is archived and is not being maintained.

ComboBox.DropDownOpened Event

Occurs when the Popup of a ComboBox opens.

Namespace: System.Windows.Controls
Assembly: PresentationFramework (in presentationframework.dll)
XML Namespace:

public event EventHandler DropDownOpened
/** @event */
public void add_DropDownOpened (EventHandler value)

/** @event */
public void remove_DropDownOpened (EventHandler value)

In JScript, you can handle the events defined by a class, but you cannot define your own.
<object DropDownOpened="EventHandler" .../>

The following example shows how to assign event handlers and handle the DropDownOpened and ComboBox.DropDownClosed events.

<ComboBox Name="cb" StaysOpenOnEdit="true" IsEditable="true" DropDownOpened="OnDropDownOpened" 

void OnDropDownOpened(object sender, EventArgs e)
if(cb.IsDropDownOpen == true)
   cb.Text="Combo box opened";

void OnDropDownClosed(object sender, EventArgs e)
if(cb.IsDropDownOpen == false)
   cb.Text="Combo box closed";

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0