IComparer.Compare(Object, Object) IComparer.Compare(Object, Object) IComparer.Compare(Object, Object) IComparer.Compare(Object, Object) Method

Definição

Compara dois objetos e retorna um valor que indica se um é menor, igual ou maior do que o outro.Compares two objects and returns a value indicating whether one is less than, equal to, or greater than the other.

public:
 int Compare(System::Object ^ x, System::Object ^ y);
public int Compare (object x, object y);
abstract member Compare : obj * obj -> int
Public Function Compare (x As Object, y As Object) As Integer

Parâmetros

x
Object Object Object Object

O primeiro objeto a ser comparado.The first object to compare.

y
Object Object Object Object

O segundo objeto a ser comparado.The second object to compare.

Retornos

Um inteiro com sinal que indica os valores relativos de x e y:A signed integer that indicates the relative values of x and y:
- Se for menor que 0, x será menor que y.- If less than 0, x is less than y.
- Se for 0, x será igual a y.- If 0, x equals y.
- Se for maior que 0, x será maior que y.- If greater than 0, x is greater than y.

..

Exceções

Nem x nem y implementam a interface IComparable.Neither x nor y implements the IComparable interface.

- ou --or- x e y são de tipos diferentes e não podem manipular comparações com os outros.x and y are of different types and neither one can handle comparisons with the other.

Exemplos

O exemplo a seguir usa a interface IComparer para classificar uma matriz de cadeia de caracteres.The following example uses the IComparer interface to sort a string array. Neste exemplo, o método Compare é implementado usando a classe CaseInsensitiveComparer para inverter a ordem do conteúdo da matriz.In this example, the Compare method is implemented using the CaseInsensitiveComparer class to reverse the order of the contents of the array.

using System;
using System.Collections;

public class Example  
{
   public class ReverserClass : IComparer  
   {
      // Call CaseInsensitiveComparer.Compare with the parameters reversed.
      int IComparer.Compare(Object x, Object y)  
      {
          return ((new CaseInsensitiveComparer()).Compare(y, x));
      }
   }

   public static void Main()  
   {
      // Initialize a string array.
      string[] words = { "The", "quick", "brown", "fox", "jumps", "over",
                         "the", "lazy", "dog" };
 
      // Display the array values.
      Console.WriteLine("The array initially contains the following values:" );
      PrintIndexAndValues(words);
 
      // Sort the array values using the default comparer.
      Array.Sort(words);
      Console.WriteLine("After sorting with the default comparer:" );
      PrintIndexAndValues(words);

      // Sort the array values using the reverse case-insensitive comparer.
      Array.Sort(words, new ReverserClass());
      Console.WriteLine("After sorting with the reverse case-insensitive comparer:");
      PrintIndexAndValues(words);

   }
 
   public static void PrintIndexAndValues(IEnumerable list)  
   {
      int i = 0;
      foreach (var item in list )
         Console.WriteLine($"   [{i++}]:  {item}");

      Console.WriteLine();
   }

}
// The example displays the following output:
//       The array initially contains the following values:
//          [0]:  The
//          [1]:  quick
//          [2]:  brown
//          [3]:  fox
//          [4]:  jumps
//          [5]:  over
//          [6]:  the
//          [7]:  lazy
//          [8]:  dog
//       
//       After sorting with the default comparer:
//          [0]:  brown
//          [1]:  dog
//          [2]:  fox
//          [3]:  jumps
//          [4]:  lazy
//          [5]:  over
//          [6]:  quick
//          [7]:  the
//          [8]:  The
//       
//       After sorting with the reverse case-insensitive comparer:
//          [0]:  the
//          [1]:  The
//          [2]:  quick
//          [3]:  over
//          [4]:  lazy
//          [5]:  jumps
//          [6]:  fox
//          [7]:  dog
//          [8]:  brown
Imports System.Collections

Public Class Example
   Public Class ReverserClass : Implements IComparer
      ' Call CaseInsensitiveComparer.Compare with the parameters reversed.
      Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer _
             Implements IComparer.Compare
         Return New CaseInsensitiveComparer().Compare(y, x)
      End Function 
   End Class

   Public Shared Sub Main()
      ' Initialize a string array.
      Dim words() As String = { "The", "quick", "brown", "fox", "jumps", "over",
                         "the", "lazy", "dog" }

      ' Display the array values.
      Console.WriteLine("The array initially contains the following values:")
      PrintIndexAndValues(words)

      ' Sort the array values of the ArrayList using the default comparer.
      Array.Sort(words)
      Console.WriteLine("After sorting with the default comparer:")
      PrintIndexAndValues(words)

      ' Sort the array values using the reverse case-insensitive comparer.
      Array.Sort(words, new ReverserClass())
      Console.WriteLine("After sorting with the reverse case-insensitive comparer:")
      PrintIndexAndValues(words)
   End Sub 

   Public Shared Sub PrintIndexAndValues(list As IEnumerable)
      Dim i As Integer = 0
      For Each item In  list
         Console.WriteLine($"   [{i}]:  {item}")
         i += 1
      Next
      Console.WriteLine()
   End Sub 
End Class
' The example displays the following output:
'       The array initially contains the following values:
'          [0]:  The
'          [1]:  quick
'          [2]:  brown
'          [3]:  fox
'          [4]:  jumps
'          [5]:  over
'          [6]:  the
'          [7]:  lazy
'          [8]:  dog
'       
'       After sorting with the default comparer:
'          [0]:  brown
'          [1]:  dog
'          [2]:  fox
'          [3]:  jumps
'          [4]:  lazy
'          [5]:  over
'          [6]:  quick
'          [7]:  the
'          [8]:  The
'       
'       After sorting with the reverse case-insensitive comparer:
'          [0]:  the
'          [1]:  The
'          [2]:  quick
'          [3]:  over
'          [4]:  lazy
'          [5]:  jumps
'          [6]:  fox
'          [7]:  dog
'          [8]:  brown

Comentários

A implementação preferida é usar o método CompareTo de um dos parâmetros.The preferred implementation is to use the CompareTo method of one of the parameters.

A comparação de null com qualquer tipo é permitida e não gera uma exceção ao usar IComparable.Comparing null with any type is allowed and does not generate an exception when using IComparable. Durante a classificação, null é considerado menor que qualquer outro objeto.When sorting, null is considered to be less than any other object.

Aplica-se a

Veja também