EventInfo.EventHandlerType Property

Reference

Definition

Namespace:: System.Reflection

Assemblies:: mscorlib.dll, System.Reflection.dll

Assemblies:: netstandard.dll, System.Runtime.dll

Assembly:: System.Reflection.dll

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Source:: EventInfo.cs

Source:: EventInfo.cs

Source:: EventInfo.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Gets the Type object of the underlying event-handler delegate associated with this event.

public:
 virtual property Type ^ EventHandlerType { Type ^ get(); };

public:
 property Type ^ EventHandlerType { Type ^ get(); };

public virtual Type EventHandlerType { get; }

public virtual Type? EventHandlerType { get; }

public Type EventHandlerType { get; }

member this.EventHandlerType : Type

Public Overridable ReadOnly Property EventHandlerType As Type

Public ReadOnly Property EventHandlerType As Type

Property Value

Type

A read-only Type object representing the delegate event handler.

Implements

EventHandlerType

Exceptions

SecurityException

The caller does not have the required permission.

Examples

The following example uses the EventHandlerType property to discover the delegate type of an event and to display its parameter types.

The example defines a delegate named MyDelegate and an event named ev of type MyDelegate. The code in the Main method discovers the event signature by getting the delegate type of the event, getting the Invoke method of the delegate type, and then retrieving and displaying the parameters.

// The following example uses instances of classes in
// the System::Reflection namespace to discover an event argument type.
using namespace System;
using namespace System::Reflection;

public delegate void MyDelegate( int i );
public ref class MainClass
{
public:
   event MyDelegate^ ev;
};

int main()
{
   Type^ delegateType = MainClass::typeid->GetEvent( "ev" )->EventHandlerType;
   MethodInfo^ invoke = delegateType->GetMethod( "Invoke" );
   array<ParameterInfo^>^pars = invoke->GetParameters();
   System::Collections::IEnumerator^ myEnum = pars->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      ParameterInfo^ p = safe_cast<ParameterInfo^>(myEnum->Current);
      Console::WriteLine( p->ParameterType );
   }
}
// The example displays the following output:
//       System.Int32

// The following example uses instances of classes in
// the System.Reflection namespace to discover an event argument type.
using System;
using System.Reflection;

public delegate void MyDelegate(int i);
public class MainClass
{
    public event MyDelegate ev;

    public static void Main()
    {
        Type delegateType = typeof(MainClass).GetEvent("ev").EventHandlerType;
        MethodInfo invoke = delegateType.GetMethod("Invoke");
        ParameterInfo[] pars = invoke.GetParameters();
        foreach (ParameterInfo p in pars)
        {
            Console.WriteLine(p.ParameterType);
        }
    }
}
// The example displays the following output:
//       System.Int32

Imports System.Reflection

Public Delegate Sub MyDelegate(ByVal i As Integer)

Public Class MainClass
    Public Event ev As MyDelegate

    Public Shared Sub Main()
        Dim delegateType As Type = GetType(MainClass).GetEvent("ev").EventHandlerType
        Dim invoke As MethodInfo = delegateType.GetMethod("Invoke")
        Dim pars As ParameterInfo() = invoke.GetParameters()
        For Each p As ParameterInfo In pars
            Console.WriteLine(p.ParameterType)
        Next 
    End Sub 
End Class 
' The example displays the following output:
'     System.Int32

Applies to

Product	Versions
.NET	Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1
UWP	10.0

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