EventDescriptor
Class
Definition
Provides information about an event.
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class EventDescriptor : System.ComponentModel.MemberDescriptor
- Inheritance
- Attributes
Inherited Members
System.ComponentModel.MemberDescriptor
System.Object
Examples
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.
for each (EventDescriptor^ myEvent in events) {
textBox1->Text += myEvent->Category + '\n';
textBox1->Text += myEvent->Description + '\n';
textBox1->Text += myEvent->DisplayName + '\n';
}
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';
}
Dim events As EventDescriptorCollection = TypeDescriptor.GetEvents(Button1)
' Displays each event's information in the collection in a text box.
Dim myEvent As EventDescriptor
For Each myEvent In events
TextBox1.Text &= myEvent.Category & ControlChars.Cr
TextBox1.Text &= myEvent.Description & ControlChars.Cr
TextBox1.Text &= myEvent.DisplayName & ControlChars.Cr
Next myEvent
Remarks
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 NIB: Raising an Event. For more information about reflection, see the topics in Reflection.
Constructors
| EventDescriptor(MemberDescriptor) |
Initializes a new instance of the EventDescriptor class with the name and attributes in the specified MemberDescriptor. |
| EventDescriptor(MemberDescriptor, Attribute[]) |
Initializes a new instance of the EventDescriptor class with the name in the specified MemberDescriptor and the attributes in both the MemberDescriptor and the Attribute array. |
| EventDescriptor(String, Attribute[]) |
Initializes a new instance of the EventDescriptor class with the specified name and attribute array. |
Properties
| ComponentType |
When overridden in a derived class, gets the type of component this event is bound to. |
| EventType |
When overridden in a derived class, gets the type of delegate for the event. |
| IsMulticast |
When overridden in a derived class, gets a value indicating whether the event delegate is a multicast delegate. |
Methods
| AddEventHandler(Object, Delegate) |
When overridden in a derived class, binds the event to the component. |
| RemoveEventHandler(Object, Delegate) |
When overridden in a derived class, unbinds the delegate from the component so that the delegate will no longer receive events from the component. |