Type.GetEvent Method

Definition

Namespace:

System

Assembly:

System.Runtime.dll

Gets a specific event declared or inherited by the current Type.

Overloads

GetEvent(String, BindingFlags)	When overridden in a derived class, returns the EventInfo object representing the specified event, using the specified binding constraints.
GetEvent(String)	Returns the EventInfo object representing the specified public event.

GetEvent(String, BindingFlags)

Source:

Type.cs

When overridden in a derived class, returns the EventInfo object representing the specified event, using the specified binding constraints.

public:
 abstract System::Reflection::EventInfo ^ GetEvent(System::String ^ name, System::Reflection::BindingFlags bindingAttr);

public abstract System.Reflection.EventInfo? GetEvent (string name, System.Reflection.BindingFlags bindingAttr);

abstract member GetEvent : string * System.Reflection.BindingFlags -> System.Reflection.EventInfo

Public MustOverride Function GetEvent (name As String, bindingAttr As BindingFlags) As EventInfo

Parameters

name

String

The string containing the name of an event which is declared or inherited by the current Type.

bindingAttr

BindingFlags

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

-or-

Default to return null.

Returns

EventInfo

The object representing the specified event that is declared or inherited by the current Type, if found; otherwise, null.

Exceptions

ArgumentNullException

name is null.

Examples

The following code example uses the GetEvent(String, BindingFlags) method to search a type for a public or non-public event named "Click" that is not static (Shared in Visual Basic).

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

using namespace System;
using namespace System::Reflection;
using namespace System::Security;
using namespace System::Windows::Forms;

int main()
{
   try
   {
      // Creates a bitmask based on BindingFlags.
      BindingFlags myBindingFlags = static_cast<BindingFlags>(BindingFlags::Instance | BindingFlags::Public | BindingFlags::NonPublic);
      Type^ myTypeBindingFlags = System::Windows::Forms::Button::typeid;
      EventInfo^ myEventBindingFlags = myTypeBindingFlags->GetEvent( "Click", myBindingFlags );
      if ( myEventBindingFlags != nullptr )
      {
         Console::WriteLine( "Looking for the Click event in the Button class with the specified BindingFlags." );
         Console::WriteLine( myEventBindingFlags );
      }
      else
            Console::WriteLine( "The Click event is not available with the Button class." );
   }
   catch ( SecurityException^ e ) 
   {
      Console::WriteLine( "An exception occurred." );
      Console::WriteLine( "Message : {0}", e->Message );
   }
   catch ( ArgumentNullException^ e ) 
   {
      Console::WriteLine( "An exception occurred." );
      Console::WriteLine( "Message : {0}", e->Message );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "The following exception was raised : {0}", e->Message );
   }
}

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

class MyEventExample
{
    public static void Main()
    {
        try
        {

            // Creates a bitmask based on BindingFlags.
            BindingFlags myBindingFlags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic;
            Type myTypeBindingFlags = typeof(System.Windows.Forms.Button);
            EventInfo myEventBindingFlags = myTypeBindingFlags.GetEvent("Click", myBindingFlags);
            if(myEventBindingFlags != null)
            {
                Console.WriteLine("Looking for the Click event in the Button class with the specified BindingFlags.");
                Console.WriteLine(myEventBindingFlags.ToString());
            }
            else
            {
                Console.WriteLine("The Click event is not available with the Button class.");
            }
        }
        catch(SecurityException e)
        {
            Console.WriteLine("An exception occurred.");
            Console.WriteLine("Message :"+e.Message);
        }
        catch(ArgumentNullException e)
        {
            Console.WriteLine("An exception occurred.");
            Console.WriteLine("Message :"+e.Message);
        }
        catch(Exception e)
        {
            Console.WriteLine("The following exception was raised : {0}",e.Message);
        }
    }
}

open System
open System.Reflection
open System.Security

try
    // Creates a bitmask based on BindingFlags.
    let myBindingFlags = BindingFlags.Instance ||| BindingFlags.Public ||| BindingFlags.NonPublic
    let myTypeBindingFlags = typeof<System.Windows.Forms.Button>
    let myEventBindingFlags = myTypeBindingFlags.GetEvent("Click", myBindingFlags)
    if myEventBindingFlags <> null then
        printfn $"Looking for the Click event in the Button class with the specified BindingFlags.\n{myEventBindingFlags}"
    else
        printfn "The Click event is not available with the Button class."
with
| :? SecurityException as e ->
    printfn "An exception occurred."
    printfn $"Message :{e.Message}"
| :? ArgumentNullException as e ->
    printfn "An exception occurred."
    printfn $"Message :{e.Message}"
| e ->
    printfn $"The following exception was raised : {e.Message}"

Imports System.Reflection
Imports System.Security

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

Class MyEventExample
    Public Shared Sub Main()
        Try
            ' Creates a bitmask comprising  BindingFlags.
            Dim myBindingFlags As BindingFlags = BindingFlags.Instance Or BindingFlags.Public _
                                                 Or BindingFlags.NonPublic
            Dim myTypeBindingFlags As Type = GetType(System.Windows.Forms.Button)
            Dim myEventBindingFlags As EventInfo = myTypeBindingFlags.GetEvent("Click", myBindingFlags)
            If myEventBindingFlags IsNot Nothing Then
                Console.WriteLine("Looking for the Click event in the Button class with the specified BindingFlags.")
                Console.WriteLine(myEventBindingFlags.ToString())
            Else
                Console.WriteLine("The Click event is not available with the Button class.")
            End If
        Catch e As SecurityException
            Console.WriteLine("An exception occurred.")
            Console.WriteLine("Message :" + e.Message)
        Catch e As ArgumentNullException
            Console.WriteLine("An exception occurred.")
            Console.WriteLine("Message :" + e.Message)
        Catch e As Exception
            Console.WriteLine("The following exception was raised : {0}", e.Message)
        End Try
    End Sub
End Class

Remarks

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.

• 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.IgnoreCase to ignore the case of name.

• 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 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

• EventInfo
• String
• BindingFlags
• DefaultBinder
• GetEvents()

GetEvent(String)

Source:

Type.cs

Returns the EventInfo object representing the specified public event.

public:
 System::Reflection::EventInfo ^ GetEvent(System::String ^ name);

public System.Reflection.EventInfo? GetEvent (string name);

member this.GetEvent : string -> System.Reflection.EventInfo

Public Function GetEvent (name As String) As EventInfo

Parameters

name

String

The string containing the name of an event that is declared or inherited by the current Type.

Returns

EventInfo

The object representing the specified public event that is declared or inherited by the current Type, if found; otherwise, null.

Exceptions

ArgumentNullException

name is null.

Examples

The following example creates an EventInfo object and gets the event for a button class for the specified event.

#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;
      EventInfo^ myEvent = myType->GetEvent( "Click" );
      if ( myEvent != nullptr )
      {
         Console::WriteLine( "Looking for the Click event in the Button class." );
         Console::WriteLine( myEvent );
      }
      else
            Console::WriteLine( "The Click event is not available in the Button class." );
   }
   catch ( SecurityException^ e ) 
   {
      Console::WriteLine( "An exception occurred." );
      Console::WriteLine( "Message : {0}", e->Message );
   }
   catch ( ArgumentNullException^ e ) 
   {
      Console::WriteLine( "An exception occurred." );
      Console::WriteLine( "Message : {0}", e->Message );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "The following exception was raised : {0}", e->Message );
   }
}

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

class MyEventExample
{
    public static void Main()
    {
        try
        {

            Type myType = typeof(System.Windows.Forms.Button);
            EventInfo myEvent = myType.GetEvent("Click");
            if(myEvent != null)
            {
                Console.WriteLine("Looking for the Click event in the Button class.");
                Console.WriteLine(myEvent.ToString());
            }
            else
            {
                Console.WriteLine("The Click event is not available in the Button class.");
            }
        }
        catch(SecurityException e)
        {
            Console.WriteLine("An exception occurred.");
            Console.WriteLine("Message :"+e.Message);
        }
        catch(ArgumentNullException e)
        {
            Console.WriteLine("An exception occurred.");
            Console.WriteLine("Message :"+e.Message);
        }
        catch(Exception e)
        {
            Console.WriteLine("The following exception was raised : {0}",e.Message);
        }
    }
}

open System
open System.Security

try
    let myType = typeof<System.Windows.Forms.Button>
    let myEvent = myType.GetEvent "Click"
    if myEvent <> null then
        printfn $"Looking for the Click event in the Button class.\n{myEvent}"
    else
        printfn "The Click event is not available in the Button class."
with
| :? SecurityException as e ->
    printfn "An exception occurred."
    printfn $"Message :{e.Message}"
| :? ArgumentNullException as e ->
    printfn "An exception occurred."
    printfn $"Message :{e.Message}"
| e ->
    printfn $"The following exception was raised : {e.Message}"

Imports System.Reflection
Imports System.Security

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

Class MyEventExample
    Public Shared Sub Main()
        Try
            Dim myType As Type = GetType(System.Windows.Forms.Button)
            Dim myEvent As EventInfo = myType.GetEvent("Click")
            If Not (myEvent Is Nothing) Then
                Console.WriteLine(ControlChars.Cr + "Looking for the Click event in the Button class.")
                Console.WriteLine(ControlChars.Cr + myEvent.ToString())
            Else
                Console.WriteLine("The Click event is not available with the Button class.")
            End If
        Catch e As SecurityException
            Console.WriteLine("An exception occurred.")
            Console.WriteLine("Message :" + e.Message)
        Catch e As ArgumentNullException
            Console.WriteLine("An exception occurred.")
            Console.WriteLine("Message :" + e.Message)
        Catch e As Exception
            Console.WriteLine("The following exception was raised : {0}", 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.

The search for name is case-sensitive. The search includes public static and public instance events.

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 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

• EventInfo
• String
• DefaultBinder
• GetEvents()