Delegate.GetInvocationList 方法

定义

命名空间:

System

程序集:

System.Runtime.dll

程序集:

netstandard.dll

程序集:

mscorlib.dll

返回委托的调用列表。

C#

public virtual Delegate[] GetInvocationList ();

返回

Delegate[]

委托构成的数组，表示当前委托的调用列表。

示例

以下示例将三种方法分配给委托。 然后，它调用 方法获取分配给委托的方法的总数，以相反的顺序执行委托，以及执行名称不包含子字符串 GetInvocationList "File"的方法。

C#

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);
   }
}

注解

数组中的每个委托只表示一个方法。

数组中委托的顺序与当前委托调用这些委托表示的方法的顺序相同。

适用于