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Type.GetEvents Method

  • Reference

Definition

Namespace:
System
Assembly:
System.Runtime.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll

Gets the events that are declared or inherited by the current Type.

Overloads

GetEvents()

Returns all the public events that are declared or inherited by the current Type.
GetEvents(BindingFlags)

When overridden in a derived class, searches for events that are declared or inherited by the current Type, using the specified binding constraints.

GetEvents()

Source:
Type.cs
Source:
Type.cs
Source:
Type.cs

Returns all the public events that are declared or inherited by the current Type.

public:
 virtual cli::array <System::Reflection::EventInfo ^> ^ GetEvents();
public virtual System.Reflection.EventInfo[] GetEvents ();
abstract member GetEvents : unit -> System.Reflection.EventInfo[]
override this.GetEvents : unit -> System.Reflection.EventInfo[]
Public Overridable Function GetEvents () As EventInfo()

Returns

EventInfo[]

An array of EventInfo objects representing all the public events which are declared or inherited by the current Type.

-or-

An empty array of type EventInfo, if the current Type does not have public events.

Implements

GetEvents()

Examples

The following example obtains an array of EventInfo objects, gets all the events for a Button class, and displays the event names. To compile the Visual Basic example, use the following command line:

vbc type_getevents1.vb /r:System.Windows.Forms.dll /r:System.dll

#using <System.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>

using namespace System;
using namespace System::Reflection;
using namespace System::Security;

int main()
{
   try
   {
      Type^ myType = System::Windows::Forms::Button::typeid;
      array<EventInfo^>^myEvents = myType->GetEvents();
      Console::WriteLine( "The events on the Button class are: " );
      for ( int index = 0; index < myEvents->Length; index++ )
      {
         Console::WriteLine( myEvents[ index ] );

      }
   }
   catch ( SecurityException^ e ) 
   {
      Console::WriteLine( "SecurityException: {0}", e->Message );
   }
   catch ( ArgumentNullException^ e ) 
   {
      Console::WriteLine( "ArgumentNullException: {0}", e->Message );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "Exception: {0}", e->Message );
   }
}

using System;
using System.Reflection;
using System.Security;

class EventsSample
{
    public static void Main()
    {
        try
        {
            // Creates a bitmask based on BindingFlags.
            BindingFlags myBindingFlags = BindingFlags.Instance | BindingFlags.Public;
            Type myTypeEvent = typeof(System.Windows.Forms.Button);
            EventInfo[] myEventsBindingFlags = myTypeEvent.GetEvents(myBindingFlags);
            Console.WriteLine("\nThe events on the Button class with the specified BindingFlags are : ");
            for (int index = 0; index < myEventsBindingFlags.Length; index++)
            {
                Console.WriteLine(myEventsBindingFlags[index].ToString());
            }
        }
        catch(SecurityException e)
        {
            Console.WriteLine("SecurityException :" + e.Message);
        }
        catch(ArgumentNullException e)
        {
            Console.WriteLine("ArgumentNullException : " + e.Message);
        }
        catch(Exception e)
        {
            Console.WriteLine("Exception : " + e.Message);
        }
    }
}

open System
open System.Reflection
open System.Security

try
    // Creates a bitmask based on BindingFlags.
    let myBindingFlags = BindingFlags.Instance ||| BindingFlags.Public
    let myTypeEvent = typeof<System.Windows.Forms.Button>
    let myEventsBindingFlags = myTypeEvent.GetEvents myBindingFlags
    printfn "\nThe events on the Button class with the specified BindingFlags are : "
    for flag in myEventsBindingFlags do
        printfn $"{flag}"
with
| :? SecurityException as e ->
    printfn $"SecurityException: {e.Message}"
| :? ArgumentNullException as e ->
    printfn $"ArgumentNullException: {e.Message}"
| e ->
    printfn $"Exception : {e.Message}"

Imports System.Reflection
Imports System.Security

' Compile this sample using the following command line:
' vbc type_getevents.vb /r:"System.Windows.Forms.dll" /r:"System.dll"

Class EventsSample

    Public Shared Sub Main()
        Try
            ' Creates a bitmask based on BindingFlags.
            Dim myBindingFlags As BindingFlags = BindingFlags.Instance Or BindingFlags.Public
            Dim myTypeEvent As Type = GetType(System.Windows.Forms.Button)
            Dim myEventsBindingFlags As EventInfo() = myTypeEvent.GetEvents(myBindingFlags)
            Console.WriteLine(ControlChars.Cr + "The events on the Button class with the specified BindingFlags are : ")
            Dim index As Integer
            For index = 0 To myEventsBindingFlags.Length - 1
                Console.WriteLine(myEventsBindingFlags(index).ToString())
            Next index
        Catch e As SecurityException
            Console.WriteLine(("SecurityException :" + e.Message))
        Catch e As ArgumentNullException
            Console.WriteLine(("ArgumentNullException : " + e.Message))
        Catch e As Exception
            Console.WriteLine(("Exception : " + e.Message))
        End Try
    End Sub
End Class

Remarks

An event is considered public to reflection if it has at least one method or accessor that is public. Otherwise the event is considered private, and you must use BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static (in Visual Basic, combine the values using Or) to get it.

In .NET 6 and earlier versions, the GetEvents method does not return events in a particular order, such as alphabetical or declaration order. Your code must not depend on the order in which events are returned, because that order varies. However, starting with .NET 7, the ordering is deterministic based upon the metadata ordering in the assembly.

This method can be overridden by a derived class.

The following table shows what members of a base class are returned by the Get methods when reflecting on a type.

Member Type Static Non-Static
Constructor No No
Field No Yes. A field is always hide-by-name-and-signature.
Event Not applicable The common type system rule is that the inheritance is the same as that of the methods that implement the property. Reflection treats properties as hide-by-name-and-signature. See note 2 below.
Method No Yes. A method (both virtual and non-virtual) can be hide-by-name or hide-by-name-and-signature.
Nested Type No No
Property Not applicable The common type system rule is that the inheritance is the same as that of the methods that implement the property. Reflection treats properties as hide-by-name-and-signature. See note 2 below.

  1. Hide-by-name-and-signature considers all of the parts of the signature, including custom modifiers, return types, parameter types, sentinels, and unmanaged calling conventions. This is a binary comparison.

  2. For reflection, properties and events are hide-by-name-and-signature. If you have a property with both a get and a set accessor in the base class, but the derived class has only a get accessor, the derived class property hides the base class property, and you will not be able to access the setter on the base class.

  3. Custom attributes are not part of the common type system.

If the current Type represents a constructed generic type, this method returns the EventInfo objects with the type parameters replaced by the appropriate type arguments.

If the current Type represents a type parameter in the definition of a generic type or generic method, this method searches the events of the class constraint.

See also

Applies to

GetEvents(BindingFlags)

Source:
Type.cs
Source:
Type.cs
Source:
Type.cs

When overridden in a derived class, searches for events that are declared or inherited by the current Type, using the specified binding constraints.

public:
 abstract cli::array <System::Reflection::EventInfo ^> ^ GetEvents(System::Reflection::BindingFlags bindingAttr);
public abstract System.Reflection.EventInfo[] GetEvents (System.Reflection.BindingFlags bindingAttr);
abstract member GetEvents : System.Reflection.BindingFlags -> System.Reflection.EventInfo[]
Public MustOverride Function GetEvents (bindingAttr As BindingFlags) As EventInfo()

Parameters

bindingAttr
BindingFlags

A bitwise combination of the enumeration values that specify how the search is conducted.

-or-

Default to return an empty array.

Returns

EventInfo[]

An array of EventInfo objects representing all events that are declared or inherited by the current Type that match the specified binding constraints.

-or-

An empty array of type EventInfo, if the current Type does not have events, or if none of the events match the binding constraints.

Implements

GetEvents(BindingFlags)

Examples

The following example obtains an array of EventInfo objects that match the specified binding flags, gets all the events for a Button class, and displays the event names. To compile the Visual Basic example, use the following command line:

vbc type_getevents2.vb /r:System.Windows.Forms.dll /r:System.dll

#using <System.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>

using namespace System;
using namespace System::Reflection;
using namespace System::Security;

int main()
{
   try
   {
      
      // Create a bitmask based on BindingFlags.
      BindingFlags myBindingFlags = static_cast<BindingFlags>(BindingFlags::Instance | BindingFlags::Public);
      Type^ myTypeEvent = System::Windows::Forms::Button::typeid;
      array<EventInfo^>^myEventsBindingFlags = myTypeEvent->GetEvents( myBindingFlags );
      Console::WriteLine( "\nThe events on the Button class with the specified BindingFlags are:" );
      for ( int index = 0; index < myEventsBindingFlags->Length; index++ )
      {
         Console::WriteLine( myEventsBindingFlags[ index ] );

      }
   }
   catch ( SecurityException^ e ) 
   {
      Console::WriteLine( "SecurityException: {0}", e->Message );
   }
   catch ( ArgumentNullException^ e ) 
   {
      Console::WriteLine( "ArgumentNullException: {0}", e->Message );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "Exception: {0}", e->Message );
   }
}

using System;
using System.Reflection;
using System.Security;

class EventsSample
{
    public static void Main()
    {
        try
        {
            // Create a bitmask based on BindingFlags.
            BindingFlags myBindingFlags = BindingFlags.Instance | BindingFlags.Public;
            Type myTypeEvent = typeof(System.Windows.Forms.Button);
            EventInfo[] myEventsBindingFlags = myTypeEvent.GetEvents(myBindingFlags);
            Console.WriteLine("\nThe events on the Button class with the specified BindingFlags are:");
            for (int index = 0; index < myEventsBindingFlags.Length; index++)
            {
                Console.WriteLine(myEventsBindingFlags[index].ToString());
            }
        }
        catch(SecurityException e)
        {
            Console.WriteLine("SecurityException:" + e.Message);
        }
        catch(ArgumentNullException e)
        {
            Console.WriteLine("ArgumentNullException: " + e.Message);
        }
        catch(Exception e)
        {
            Console.WriteLine("Exception: " + e.Message);
        }
    }
}

open System
open System.Reflection
open System.Security

try
    // Creates a bitmask based on BindingFlags.
    let myBindingFlags = BindingFlags.Instance ||| BindingFlags.Public
    let myTypeEvent = typeof<System.Windows.Forms.Button>
    let myEventsBindingFlags = myTypeEvent.GetEvents myBindingFlags
    printfn "\nThe events on the Button class with the specified BindingFlags are : "
    for flag in myEventsBindingFlags do
        printfn $"{flag}"
with
| :? SecurityException as e ->
    printfn $"SecurityException: {e.Message}"
| :? ArgumentNullException as e ->
    printfn $"ArgumentNullException: {e.Message}"
| e ->
    printfn $"Exception : {e.Message}"

Imports System.Reflection
Imports System.Security
Imports System.Windows.Forms

Class EventsSample

    Public Shared Sub Main()
        Try
            ' Create a bitmask based on BindingFlags.
            Dim myBindingFlags As BindingFlags = BindingFlags.Instance Or BindingFlags.Public
            Dim myTypeEvent As Type = GetType(System.Windows.Forms.Button)
            Dim myEventsBindingFlags As EventInfo() = myTypeEvent.GetEvents(myBindingFlags)
            Console.WriteLine(ControlChars.Cr + "The events on the Button class with the specified BindingFlags are:")
            Dim index As Integer
            For index = 0 To myEventsBindingFlags.Length - 1
                Console.WriteLine(myEventsBindingFlags(index).ToString())
            Next index
        Catch e As SecurityException
            Console.WriteLine("SecurityException:" + e.Message)
        Catch e As ArgumentNullException
            Console.WriteLine("ArgumentNullException: " + e.Message)
        Catch e As Exception
            Console.WriteLine("Exception: " + e.Message)
        End Try
    End Sub
End Class

Remarks

In .NET 6 and earlier versions, the GetEvents method does not return events in a particular order, such as alphabetical or declaration order. Your code must not depend on the order in which events are returned, because that order varies. However, starting with .NET 7, the ordering is deterministic based upon the metadata ordering in the assembly.

The following BindingFlags filter flags can be used to define which events to include in the search:

  • You must specify either BindingFlags.Instance or BindingFlags.Static in order to get a return.

  • Specify BindingFlags.Public to include public events in the search.

  • Specify BindingFlags.NonPublic to include non-public events (that is, private, internal, and protected events) in the search. Only protected and internal events on base classes are returned; private events on base classes are not returned.

  • Specify BindingFlags.FlattenHierarchy to include public and protected static members up the hierarchy; private static members in inherited classes are not included.

The following BindingFlags modifier flags can be used to change how the search works:

  • BindingFlags.DeclaredOnly to search only the events declared on the Type, not events that were simply inherited.

See System.Reflection.BindingFlags for more information.

An event is considered public to reflection if it has at least one method or accessor that is public. Otherwise the event is considered private, and you must use BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static (in Visual Basic, combine the values using Or) to get it.

If the current Type represents a constructed generic type, this method returns the EventInfo objects with the type parameters replaced by the appropriate type arguments.

If the current Type represents a type parameter in the definition of a generic type or generic method, this method searches the events of the class constraint.

See also

Applies to