共用方式為


EventInfo Class

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Discovers the attributes of an event and provides access to event metadata.

Inheritance Hierarchy

System.Object
  System.Reflection.MemberInfo
    System.Reflection.EventInfo

Namespace:  System.Reflection
Assembly:  mscorlib (in mscorlib.dll)

Syntax

'Declaration
<ComVisibleAttribute(True)> _
<ClassInterfaceAttribute(ClassInterfaceType.None)> _
Public MustInherit Class EventInfo _
    Inherits MemberInfo
[ComVisibleAttribute(true)]
[ClassInterfaceAttribute(ClassInterfaceType.None)]
public abstract class EventInfo : MemberInfo

The EventInfo type exposes the following members.

Constructors

  Name Description
Protected method EventInfo Initializes a new instance of the EventInfo class.

Top

Properties

  Name Description
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 Attributes Gets the attributes for this event.
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 DeclaringType Gets the class that declares this member. (Inherited from MemberInfo.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 EventHandlerType Gets the Type object of the underlying event-handler delegate associated with this event.
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 IsMulticast Gets a value that indicates whether the event is multicast.
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 IsSpecialName Gets a value that indicates whether the EventInfo has a name with a special meaning.
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 MemberType Gets a MemberTypes value indicating that this member is an event. (Overrides MemberInfo.MemberType.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 MetadataToken Gets a value that identifies a metadata element. (Inherited from MemberInfo.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 Module Gets the module in which the type that declares the member represented by the current MemberInfo is defined. (Inherited from MemberInfo.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 Name Gets the name of the current member. (Inherited from MemberInfo.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 ReflectedType Gets the class object that was used to obtain this instance of MemberInfo. (Inherited from MemberInfo.)

Top

Methods

  Name Description
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 AddEventHandler Adds an event handler to an event source.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 Finalize Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetAddMethod() Returns the method that is used to add an event-handler delegate to the event source.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetAddMethod(Boolean) When overridden in a derived class, returns the method that is used to add an event-handler delegate to the event source, specifying whether to return the method if the current event is non-public.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetCustomAttributes(Boolean) When overridden in a derived class, returns an array of all custom attributes applied to this member. (Inherited from MemberInfo.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetCustomAttributes(Type, Boolean) When overridden in a derived class, returns an array of custom attributes applied to this member and identified by Type. (Inherited from MemberInfo.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetRaiseMethod() Returns the method that is called when the event is raised.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetRaiseMethod(Boolean) When overridden in a derived class, returns the method that is called when the event is raised, specifying whether to return non-public methods.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetRemoveMethod() Returns the method that is used to remove an event-handler delegate from the event source.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetRemoveMethod(Boolean) When overridden in a derived class, retrieves the MethodInfo object for removing a method of the event, specifying whether to return non-public methods.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetType Gets the Type of the current instance. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 IsDefined When overridden in a derived class, indicates whether one or more attributes of the specified type or of its derived types is applied to this member. (Inherited from MemberInfo.)
Protected methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 RemoveEventHandler Removes an event handler from an event source.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 ToString Returns a string that represents the current object. (Inherited from Object.)

Top

Remarks

Use the EventInfo class to inspect events and to hook up event handlers, as shown in the example code for the AddEventHandler method.

NoteNote:

EventInfo is not intended to be used to raise events. An object raises events as dictated by its internal state.

Calling ICustomAttributeProvider.GetCustomAttributes on EventInfo when the inherit parameter of GetCustomAttributes is true does not walk the type hierarchy. You can use System.Attribute to walk the type hierarchy for custom attributes, but only if all the attributes derive from System.Attribute.

In Silverlight, you cannot inherit from EventInfo.

Examples

The following code gets an EventInfo object for the MouseLeftButtonUp event of a TextBlock control.

Imports System.Reflection

Class Example

    Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

        Dim myType As Type = outputBlock.GetType()

        Dim myEvent As EventInfo = myType.GetEvent("MouseLeftButtonUp", _
            BindingFlags.Instance Or BindingFlags.Public)

        If Not (myEvent Is Nothing) Then
            outputBlock.Text &= "Looking for the MouseLeftButtonUp event in the " & _
                myType.FullName & " class." & vbCrLf
            outputBlock.Text &= myEvent.ToString() & vbCrLf
        Else
            outputBlock.Text &= "The MouseLeftButtonUp event is not found in the " & _
                myType.FullName & " class." & vbCrLf
        End If

   End Sub 
End Class 

' This example produces the following output:
'
'Looking for the MouseLeftButtonUp event in the System.Windows.Controls.TextBlock class.
'System.Windows.Input.MouseButtonEventHandler MouseLeftButtonUp
using System.Reflection;
using System;

class Example
{
    public static void Demo(System.Windows.Controls.TextBlock outputBlock)
    {
        Type myType = outputBlock.GetType();

        EventInfo myEvent = myType.GetEvent("MouseLeftButtonUp", 
            BindingFlags.Instance | BindingFlags.Public);

        if (myEvent != null)
        {
            outputBlock.Text += "Looking for the MouseLeftButtonUp event in the " +
                myType.FullName + " class.\n";
            outputBlock.Text += myEvent.ToString() + "\n";
        }
        else
        {
            outputBlock.Text += "The MouseLeftButtonUp event is not found in the " +
                myType.FullName + " class.\r\n";
        }
    }
}

/* This example produces the following output:

Looking for the MouseLeftButtonUp event in the System.Windows.Controls.TextBlock class.
System.Windows.Input.MouseButtonEventHandler MouseLeftButtonUp
 */

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

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

See Also

Reference