Action<T1,T2,T3,T4> Delegado

Definición

Encapsula un método que tiene cuatro parámetros y no devuelve un valor.Encapsulates a method that has four parameters and does not return a value.

generic <typename T1, typename T2, typename T3, typename T4>
public delegate void Action(T1 arg1, T2 arg2, T3 arg3, T4 arg4);
public delegate void Action<in T1,in T2,in T3,in T4>(T1 arg1, T2 arg2, T3 arg3, T4 arg4);
type Action<'T1, 'T2, 'T3, 'T4> = delegate of 'T1 * 'T2 * 'T3 * 'T4 -> unit
Public Delegate Sub Action(Of In T1, In T2, In T3, In T4)(arg1 As T1, arg2 As T2, arg3 As T3, arg4 As T4)

Parámetros de tipo

T1

Tipo del primer parámetro del método que este delegado encapsula.The type of the first parameter of the method that this delegate encapsulates.

T2

Tipo del segundo parámetro del método que este delegado encapsula.The type of the second parameter of the method that this delegate encapsulates.

T3

Tipo del tercer parámetro del método que este delegado encapsula.The type of the third parameter of the method that this delegate encapsulates.

T4

Tipo del cuarto parámetro del método que este delegado encapsula.The type of the fourth parameter of the method that this delegate encapsulates.

Parámetros

arg1

Primer parámetro del método que este delegado encapsula.The first parameter of the method that this delegate encapsulates.

arg2

Segundo parámetro del método que este delegado encapsula.The second parameter of the method that this delegate encapsulates.

arg3

Tercer parámetro del método que este delegado encapsula.The third parameter of the method that this delegate encapsulates.

arg4

Cuarto parámetro del método que este delegado encapsula.The fourth parameter of the method that this delegate encapsulates.

Herencia
Action<T1,T2,T3,T4>

Comentarios

Puede usar el Action<T1,T2,T3,T4> delegado para pasar un método como un parámetro sin declarar explícitamente un delegado personalizado.You can use the Action<T1,T2,T3,T4> delegate to pass a method as a parameter without explicitly declaring a custom delegate. El método encapsulado debe corresponder a la firma del método que define este delegado.The encapsulated method must correspond to the method signature that is defined by this delegate. Esto significa que el método encapsulado debe tener cuatro parámetros que se le pasan por valor, y no debe devolver un valor.This means that the encapsulated method must have four parameters that are all passed to it by value, and it must not return a value. (En C#, el método debe devolver void.(In C#, the method must return void. En Visual Basic, debe definirse mediante Sub...End SubIn Visual Basic, it must be defined by the SubEnd Sub construir.construct. También puede ser un método que devuelve un valor que se omite). Normalmente, este tipo de método se utiliza para realizar una operación.It can also be a method that returns a value that is ignored.) Typically, such a method is used to perform an operation.

Nota

Para hacer referencia a un método que tiene cuatro parámetros y devuelve un valor, utilice Func<T1,T2,T3,T4,TResult> en su lugar el delegado genérico.To reference a method that has four parameters and returns a value, use the generic Func<T1,T2,T3,T4,TResult> delegate instead.

Cuando se usa el Action<T1,T2,T3,T4> delegado, no es necesario definir explícitamente un delegado que encapsula un método con cuatro parámetros.When you use the Action<T1,T2,T3,T4> delegate, you do not have to explicitly define a delegate that encapsulates a method with four parameters. Por ejemplo, el código siguiente declara explícitamente un delegado denominado StringCopy y asigna una referencia CopyStrings al método a su instancia de delegado.For example, the following code explicitly declares a delegate named StringCopy and assigns a reference to the CopyStrings method to its delegate instance.

using System;

delegate void StringCopy(string[] stringArray1, 
                         string[] stringArray2, 
                         int indexToStart,
                         int numberToCopy);
                         
public class TestDelegate
{
   public static void Main()
   {
      string[] ordinals = {"First", "Second", "Third", "Fourth", "Fifth", 
                           "Sixth", "Seventh", "Eighth", "Ninth", "Tenth"};
      string[] copiedOrdinals = new string[ordinals.Length];           
      StringCopy copyOperation = CopyStrings;
      copyOperation(ordinals, copiedOrdinals, 3, 5);
      foreach (string ordinal in copiedOrdinals)
         Console.WriteLine(String.IsNullOrEmpty(ordinal) ? "<None>" : ordinal);
   }

   private static void CopyStrings(string[] source, string[] target, 
                                   int startPos, int number)
   {
      if (source.Length != target.Length) 
         throw new IndexOutOfRangeException("The source and target arrays must have the same number of elements.");

      for (int ctr = startPos; ctr <= startPos + number - 1; ctr++)
         target[ctr] = String.Copy(source[ctr]);
   }
}
Delegate Sub StringCopy(stringArray1() As String, _
                        stringArray2() As String, _
                        indexToStart As Integer, _
                        numberToCopy As Integer)

Module TestDelegate
   Public Sub Main()
      Dim ordinals() As String = {"First", "Second", "Third", "Fourth", _
                                  "Fifth", "Sixth", "Seventh", "Eighth", _
                                  "Ninth", "Tenth"}
      Dim copiedOrdinals(ordinals.Length - 1) As String
      Dim copyOperation As StringCopy = AddressOf CopyStrings
      copyOperation(ordinals, copiedOrdinals, 3, 5)
      For Each ordinal As String In copiedOrdinals
         Console.WriteLine(ordinal)
      Next    
   End Sub
   
   Private Sub CopyStrings(source() As String, target() As String, _
                           startPos As Integer, number As Integer)
      If source.Length <> target.Length Then 
         Throw New IndexOutOfRangeException("The source and target arrays" & _
                   " must have the same number of elements.")
      End If
      For ctr As Integer = startPos to startpos + number  - 1
         target(ctr) = String.Copy(source(ctr))
      Next
   End Sub
End Module

En el ejemplo siguiente se simplifica este código creando una instancia Action<T1,T2,T3,T4> del delegado en lugar de definir explícitamente un nuevo delegado y asignarle un método con nombre.The following example simplifies this code by instantiating the Action<T1,T2,T3,T4> delegate instead of explicitly defining a new delegate and assigning a named method to it.

using System;

public class TestAction4
{
   public static void Main()
   {
      string[] ordinals = {"First", "Second", "Third", "Fourth", "Fifth", 
                           "Sixth", "Seventh", "Eighth", "Ninth", "Tenth"};
      string[] copiedOrdinals = new string[ordinals.Length];           
      Action<string[], string[], int, int> copyOperation = CopyStrings;
      copyOperation(ordinals, copiedOrdinals, 3, 5);
      foreach (string ordinal in copiedOrdinals)
         Console.WriteLine(String.IsNullOrEmpty(ordinal) ? "<None>" : ordinal);
   }

   private static void CopyStrings(string[] source, string[] target, 
                                   int startPos, int number)
   {
      if (source.Length != target.Length) 
         throw new IndexOutOfRangeException("The source and target arrays must have the same number of elements.");

      for (int ctr = startPos; ctr <= startPos + number - 1; ctr++)
         target[ctr] = String.Copy(source[ctr]);
   }
}
Module TestAction4
   Public Sub Main()
      Dim ordinals() As String = {"First", "Second", "Third", "Fourth", _
                                  "Fifth", "Sixth", "Seventh", "Eighth", _
                                  "Ninth", "Tenth"}
      Dim copiedOrdinals(ordinals.Length - 1) As String
      Dim copyOperation As Action(Of String(), String(), Integer, Integer) = _
                           AddressOf CopyStrings
      copyOperation(ordinals, copiedOrdinals, 3, 5)
      For Each ordinal As String In copiedOrdinals
         Console.WriteLine(ordinal)
      Next    
   End Sub
   
   Private Sub CopyStrings(source() As String, target() As String, _
                           startPos As Integer, number As Integer)
      If source.Length <> target.Length Then 
         Throw New IndexOutOfRangeException("The source and target arrays" & _
                   " must have the same number of elements.")
      End If
      For ctr As Integer = startPos to startpos + number  - 1
         target(ctr) = String.Copy(source(ctr))
      Next
   End Sub
End Module

También puede usar el Action<T1,T2,T3,T4> delegado con métodos anónimos en, como se muestra en C#el ejemplo siguiente.You can also use the Action<T1,T2,T3,T4> delegate with anonymous methods in C#, as the following example illustrates. (Para obtener una introducción a los métodos anónimos, consulte métodos anónimos).(For an introduction to anonymous methods, see Anonymous Methods.)

using System;

public class TestAnonymousMethod
{
   public static void Main()
   {
      string[] ordinals = {"First", "Second", "Third", "Fourth", "Fifth", 
                           "Sixth", "Seventh", "Eighth", "Ninth", "Tenth"};
      string[] copiedOrdinals = new string[ordinals.Length];           
      Action<string[], string[], int, int> copyOperation = 
                                           delegate(string[] s1, string[] s2, 
                                           int pos, int num) 
                                { CopyStrings(s1, s2, pos, num); };  
      copyOperation(ordinals, copiedOrdinals, 3, 5);
      foreach (string ordinal in copiedOrdinals)
         Console.WriteLine(String.IsNullOrEmpty(ordinal) ? "<None>" : ordinal);
   }

   private static void CopyStrings(string[] source, string[] target, 
                                   int startPos, int number)
   {
      if (source.Length != target.Length) 
         throw new IndexOutOfRangeException("The source and target arrays must have the same number of elements.");

      for (int ctr = startPos; ctr <= startPos + number - 1; ctr++)
         target[ctr] = String.Copy(source[ctr]);
   }
}

También puede asignar una expresión lambda a una Action<T1,T2,T3,T4> instancia de delegado, como se muestra en el ejemplo siguiente.You can also assign a lambda expression to an Action<T1,T2,T3,T4> delegate instance, as the following example illustrates. (Para ver una introducción a las expresiones lambda, vea expresiones lambda).(For an introduction to lambda expressions, see Lambda Expressions.)

using System;

public class TestLambdaExpression
{
   public static void Main()
   {
      string[] ordinals = {"First", "Second", "Third", "Fourth", "Fifth", 
                           "Sixth", "Seventh", "Eighth", "Ninth", "Tenth"};
      string[] copiedOrdinals = new string[ordinals.Length];           
      Action<string[], string[], int, int> copyOperation = (s1, s2, pos, num)
                                           => CopyStrings(s1, s2, pos, num);  
      copyOperation(ordinals, copiedOrdinals, 3, 5);
      foreach (string ordinal in copiedOrdinals)
         Console.WriteLine(String.IsNullOrEmpty(ordinal) ? "<None>" : ordinal);
   }

   private static void CopyStrings(string[] source, string[] target, 
                                   int startPos, int number)
   {
      if (source.Length != target.Length) 
         throw new IndexOutOfRangeException("The source and target arrays must have the same number of elements.");

      for (int ctr = startPos; ctr <= startPos + number - 1; ctr++)
         target[ctr] = String.Copy(source[ctr]);
   }
}
Public Module TestLambdaExpression
   Public Sub Main()
      Dim ordinals() As String = {"First", "Second", "Third", "Fourth", "Fifth", _ 
                           "Sixth", "Seventh", "Eighth", "Ninth", "Tenth"}
      Dim copiedOrdinals(ordinals.Length - 1) As String           
      Dim copyOperation As Action(Of String(), String(), Integer, Integer) = _
                           Sub(s1, s2, pos, num) CopyStrings(s1, s2, pos, num)  
      copyOperation(ordinals, copiedOrdinals, 3, 5)
      For Each ordinal As String In copiedOrdinals
         If String.IsNullOrEmpty(ordinal) Then
            Console.WriteLine("<None>")
         Else
            Console.WriteLine(ordinal)
         End If
      Next   
   End Sub

   Private Function CopyStrings(source() As String, target() As String, _ 
                                startPos As Integer, number As Integer) As Integer
      If source.Length <> target.Length Then 
         throw new IndexOutOfRangeException("The source and target arrays must have the same number of elements.")
      End If
      
      For ctr As Integer = startPos To startPos + number - 1
         target(ctr) = String.Copy(source(ctr))
      Next
      Return number
   End Function
End Module
' The example displays the following output:
'       Fourth
'       Fifth
'       Sixth
'       Seventh
'       Eighth

Métodos de extensión

GetMethodInfo(Delegate)

Obtiene un objeto que representa el método representado por el delegado especificado.Gets an object that represents the method represented by the specified delegate.

Se aplica a

Consulte también: