Delegate.GetInvocationList Delegate.GetInvocationList Delegate.GetInvocationList Delegate.GetInvocationList Method

Definition

Returns the invocation list of the delegate.

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

Returns

An array of delegates representing the invocation list of the current delegate.

Examples

The following example assigns three methods to a delegate. It then calls the GetInvocationList method to get a total count of the methods assigned to the delegate, to execute the delegates in reverse order, and to execute the methods whose name do not include the substring "File".

using System;
using System.IO;
using System.Reflection;
using System.Windows.Forms;

public class Example
{
   public static void Main()
   {
      Action<String> outputMessage = null;
      outputMessage += Console.WriteLine;
      outputMessage += OutputToFile;
      outputMessage += ShowMessageBox;

//       Dim output1 As Action(Of String) = AddressOf Console.WriteLine
//       Dim output2 As Action(Of String) = AddressOf OutputToFile 
//       Dim output3 As Action(Of String) = AddressOf MessageBox.Show
//       
//       outputMessage = [Delegate].Combine( { output1, output2, output3 } )
      Console.WriteLine("Invocation list has {0} methods.", 
                        outputMessage.GetInvocationList().Length);

      // Invoke delegates normally.
      outputMessage("Hello there!");
      Console.WriteLine("Press <Enter> to continue...");
      Console.ReadLine();
      
      // Invoke each delegate in the invocation list in reverse order.
      for (int ctr = outputMessage.GetInvocationList().Length - 1; ctr >= 0; ctr--) {
         var outputMsg = outputMessage.GetInvocationList()[ctr];
         outputMsg.DynamicInvoke("Greetings and salutations!");
      }
      Console.WriteLine("Press <Enter> to continue...");
      Console.ReadLine();

      // Invoke each delegate that doesn't write to a file.
      for (int ctr = 0; ctr < outputMessage.GetInvocationList().Length; ctr++) {  
         var outputMsg = outputMessage.GetInvocationList()[ctr];
         if (! outputMsg.GetMethodInfo().Name.Contains("File"))
            outputMsg.DynamicInvoke( new String[] { "Hi!" } );
         
      }
   }

   private static void OutputToFile(String s)
   {
      var sw = new StreamWriter(@".\output.txt");
      sw.WriteLine(s);
      sw.Close();
   }

   private static void ShowMessageBox(String s)
   {
      MessageBox.Show(s);
   }
}
Imports System.IO
Imports System.Reflection
Imports System.Windows.Forms

Module Example
   Public outputMessage As Action(Of String)
   
   Public Sub Main()
      Dim output1 As Action(Of String) = AddressOf Console.WriteLine
      Dim output2 As Action(Of String) = AddressOf OutputToFile 
      Dim output3 As Action(Of String) = AddressOf MessageBox.Show
      
      outputMessage = [Delegate].Combine( { output1, output2, output3 } )
      Console.WriteLine("Invocation list has {0} methods.", 
                        outputMessage.GetInvocationList().Count)

      ' Invoke delegates normally.
      outputMessage("Hello there!")
      Console.WriteLine("Press <Enter> to continue...")
      Console.ReadLine()
      
      ' Invoke each delegate in the invocation list in reverse order.
      For ctr As Integer = outputMessage.GetInvocationList().Count - 1 To 0 Step -1
          Dim outputMsg = outputMessage.GetInvocationList(ctr)
          outputMsg.DynamicInvoke("Greetings and salutations!")
      Next
      Console.WriteLine("Press <Enter> to continue...")
      Console.ReadLine()
      
      ' Invoke each delegate that doesn't write to a file.
      For ctr As Integer = 0 To outputMessage.GetInvocationList().Count - 1 
         Dim outputMsg = outputMessage.GetInvocationList(ctr)
         If Not outputMsg.GetMethodInfo().Name.Contains("File") Then
            outputMsg.DynamicInvoke( { "Hi!" } )
         End If
      Next
   End Sub
   
   Private Sub OutputToFile(s As String)
      Dim sw As New StreamWriter(".\output.txt")
      sw.WriteLine(s)
      sw.Close()
   End Sub
End Module

Remarks

Each delegate in the array represents exactly one method.

The order of the delegates in the array is the same order in which the current delegate invokes the methods that those delegates represent.

Security

ReflectionPermission
when invoked late-bound through mechanisms such as InvokeMember(String, BindingFlags, Binder, Object, Object[], ParameterModifier[], CultureInfo, String[]). Associated enumeration: MemberAccess

Applies to