Tuple<T1>.IStructuralEquatable.Equals(Object, IEqualityComparer) Tuple<T1>.IStructuralEquatable.Equals(Object, IEqualityComparer) Tuple<T1>.IStructuralEquatable.Equals(Object, IEqualityComparer) Method

Définition

Retourne une valeur qui indique si l'objet Tuple<T1> actif est égal à un objet spécifié selon une méthode de comparaison spécifiée.Returns a value that indicates whether the current Tuple<T1> object is equal to a specified object based on a specified comparison method.

 virtual bool System.Collections.IStructuralEquatable.Equals(System::Object ^ other, System::Collections::IEqualityComparer ^ comparer) = System::Collections::IStructuralEquatable::Equals;
bool IStructuralEquatable.Equals (object other, System.Collections.IEqualityComparer comparer);
Function Equals (other As Object, comparer As IEqualityComparer) As Boolean Implements IStructuralEquatable.Equals

Paramètres

other
Object Object Object

Objet à comparer avec cette instance.The object to compare with this instance.

comparer
IEqualityComparer IEqualityComparer IEqualityComparer

Un objet qui définit la méthode à utiliser pour évaluer si les deux objets sont égaux.An object that defines the method to use to evaluate whether the two objects are equal.

Retours

true si l'instance actuelle est égale à l'objet spécifié ; sinon, false.true if the current instance is equal to the specified object; otherwise, false.

Implémente

Exemples

L’exemple suivant définit un IEqualityComparer implémentation qui considère que deux valeurs à virgule flottante sont égales si elles sont approximativement égales entre eux (autrement dit, si une valeur se trouve dans %.01 de l’autre).The following example defines an IEqualityComparer implementation that considers two floating-point values to be equal if they are approximately equal to each other (that is, if one value is within .01 percent of the other).

using System;
using System.Collections;

public class Tuple1Comparer : IEqualityComparer
{
   new public bool Equals(object x, object y)
   {
      // Check if x is a floating point type. If x is, then y is.
      if (x is double | x is float)
      {   
         // Convert to Double values.
         double dblX = (double) x;
         double dblY = (double) y;
         if (Double.IsNaN(dblX) | Double.IsInfinity(dblX) |
             Double.IsNaN(dblY) | Double.IsInfinity(dblY)) 
            return dblX.Equals(dblY);   
         else
            return Math.Abs(dblX - dblY) <= dblX * .0001;
      }
      else
      {
         return x.Equals(y);
      }
   }
   
   public int GetHashCode(object obj)
   {
      return obj.GetHashCode();
   }
}

public class Example
{
   public static void Main()
   {
      var doubleTuple1 = Tuple.Create(12.3455);

      var doubleTuple2 = Tuple.Create(16.8912);
      var doubleTuple3 = Tuple.Create(12.3449599);

      // Compare first tuple with a Tuple<double> with a different value.
      TestEquality(doubleTuple1, doubleTuple2);
      //Compare first tuple with a Tuple<double> with the same value.
      TestEquality(doubleTuple1, doubleTuple3);
   }

   private static void TestEquality(Tuple<double> tuple, object obj)
   {
      Console.WriteLine("{0} = {1}: {2}", tuple.ToString(),
                                             obj.ToString(),
                                             ((IStructuralEquatable)tuple).Equals(obj, new Tuple1Comparer()));
   }
}
// The example displays the following output:
//       (12.3455) = (16.8912): False
//       (12.3455) = (12.3449599): True
Imports System.Collections

Public Class Tuple1Comparer : Implements IEqualityComparer
   Public Overloads Function Equals(x As Object, y As Object) As Boolean _
                   Implements IEqualityComparer.Equals
      ' Check if x is a floating point type. If x is, then y is.
      If TypeOf x Is Double Or TypeOf x Is Single Then   
         ' Convert to Double values.
         Dim dblX As Double = CDbl(x)
         Dim dblY As Double = CDbl(y)
         If Double.IsNan(dblX) Or Double.IsInfinity(dblX) Or _
            Double.IsNan(dblY) Or Double.IsInfinity(dblY) Then
            Return dblX.Equals(dblY)   
         Else
            Return Math.Abs(dblX - dblY) <= dblY * .0001
         End If
      Else
         Return x.Equals(y)
      End If                    
   End Function
   
   Public Overloads Function GetHashCode(obj As Object) As Integer _
                   Implements IEqualityComparer.GetHashCode
      Return obj.GetHashCode()
   End Function
End Class

Module Example
   Public Sub Main()
      Dim doubleTuple1 = Tuple.Create(12.3455)

      Dim doubleTuple2 = Tuple.Create(16.8912)
      Dim doubleTuple3 = Tuple.Create(12.3449599)

      ' Compare first tuple with a Tuple(Of Double) with a different value.
      TestEquality(doubleTuple1, doubleTuple2)
      ' Compare first tuple with a Tuple(Of Double) with the same value.
      TestEquality(doubleTuple1, doubleTuple3)
   End Sub

   Private Sub TestEquality(tuple As Tuple(Of Double), obj As Object)
      Try
         Console.WriteLine("{0} = {1}: {2}", tuple.ToString(),
                                             obj.ToString,
                                             DirectCAst(tuple, IStructuralEquatable).Equals(obj, New Tuple1Comparer()))
      
      Catch e As ArgumentException
         If obj.GetType.IsGenericType Then 
            If obj.GetType().Name = "Tuple`1" Then 
               Console.WriteLine("Cannot compare a Tuple(Of {0}) with a Tuple(Of {1}).", 
                              tuple.Item1.GetType().Name, obj.Item1.GetType().Name)
            Else
               Console.WriteLine("Cannot compare a {0} with a {1}.", tuple.GetType().Name, 
                                                                     obj.GetType().Name)
            End If
         Else
            Console.WriteLine("Cannot compare a {0} with a {1}.", tuple.GetType().Name,
                                                                  obj.GetType().Name)
         End If
      End Try
   End Sub
End Module
' The example displays the following output:
'       (12.3455) = (16.8912): False
'       (12.3455) = (12.3449599): True

Remarques

Ce membre est une implémentation d'un membre d'interface explicite.This member is an explicit interface member implementation. Il peut uniquement être utilisé lorsque l'instance de Tuple<T1> est castée en interface IStructuralEquatable.It can be used only when the Tuple<T1> instance is cast to an IStructuralEquatable interface.

Le IEqualityComparer.Equals implémentation est appelée uniquement si other n’est pas null, et si elle peut être casté (en c#) ou converti (en Visual Basic) en un Tuple<T1> objet dont le composant unique est du même type que l’instance actuelle.The IEqualityComparer.Equals implementation is called only if other is not null, and if it can be successfully cast (in C#) or converted (in Visual Basic) to a Tuple<T1> object whose single component is of the same type as the current instance. Est passé à la méthode le Item1 composant de l’instance actuelle et la Item1 composant de la Tuple<T1> objet représenté par le other paramètre.The method is passed the Item1 component of the current instance and the Item1 component of the Tuple<T1> object represented by the other parameter.

S’applique à

Voir aussi