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EventDescriptor Class

Provides information about an event.

Namespace:  System.ComponentModel
Assembly:  System (in System.dll)

[HostProtectionAttribute(SecurityAction.LinkDemand, SharedState = true)]
public abstract class EventDescriptor : MemberDescriptor


The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: SharedState. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

An EventDescriptor consists of a name, its attributes, the component that the event is bound to, the event delegate, the type of delegate, and whether the delegate is multicast.

EventDescriptor provides the following abstract properties and methods:

  • ComponentType contains the type of the component this event is declared on.

  • EventType contains the type of delegate for the event.

  • IsMulticast contains a value indicating whether the event delegate is a multicast delegate.

  • AddEventHandler binds the event to a component.

  • RemoveEventHandler unbinds the delegate from the component so that the delegate no longer receives events from the component.

For more information about events, see Raising an Event. For more information about reflection, see the topics in Reflection.

The following code example is built upon the example in the EventDescriptorCollection class. It prints the information (category, description, and display name) of each event on a button in a text box. It requires that button1 and textbox1 have been instantiated on a form.

EventDescriptorCollection events = TypeDescriptor.GetEvents(button1);
// Displays each event's information in the collection in a text box. 
foreach (System.ComponentModel.EventDescriptor myEvent in events) {
    textBox1.Text += myEvent.Category + '\n';
    textBox1.Text += myEvent.Description + '\n';
    textBox1.Text += myEvent.DisplayName + '\n';


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0