Tuple<T1,T2>.IStructuralComparable.CompareTo(Object, IComparer) 方法

定义

使用指定的比较器将当前的 Tuple<T1,T2> 对象与指定对象进行比较,并返回一个整数,该整数指示当前对象在排序顺序中的位置是在指定对象之前、之后还是与其相同。Compares the current Tuple<T1,T2> object to a specified object by using a specified comparer, and returns an integer that indicates whether the current object is before, after, or in the same position as the specified object in the sort order.

 virtual int System.Collections.IStructuralComparable.CompareTo(System::Object ^ other, System::Collections::IComparer ^ comparer) = System::Collections::IStructuralComparable::CompareTo;
int IStructuralComparable.CompareTo (object other, System.Collections.IComparer comparer);
Function CompareTo (other As Object, comparer As IComparer) As Integer Implements IStructuralComparable.CompareTo

参数

other
Object

要与当前实例进行比较的对象。An object to compare with the current instance.

comparer
IComparer

提供用于比较的自定义规则的对象。An object that provides custom rules for comparison.

返回

一个带符号整数,指示此实例和 other 在排序顺序中的相对位置,如下表所示。A signed integer that indicates the relative position of this instance and other in the sort order, as shown in the following table.

Value 说明Description
负整数A negative integer 此实例位于 other 之前。This instance precedes other.
Zero 此实例在排序顺序中的位置与 other 相同。This instance and other have the same position in the sort order.
正整数A positive integer 此实例位于 other 之后。This instance follows other.

实现

异常

other 不是 Tuple<T1,T2> 对象。other is not a Tuple<T1,T2> object.

示例

下面的示例创建Tuple<T1,T2>对象的数组, 其中包含学生的姓名和测试分数。The following example creates an array of Tuple<T1,T2> objects that consist of a student's name and test score. 它以未排序的顺序显示数组中每个元组的组件, 对数组进行排序, ToString然后调用以按排序顺序显示每个元组的值。It displays the component of each tuple in the array in unsorted order, sorts the array, and then calls ToString to display the value of each tuple in sorted order. 为了对数组进行排序, 此示例定义了ScoreComparer一个泛型类, IComparer该类实现接口, Tuple<T1,T2>并按其第二个组件的值 (而不是第一个组件) 对对象进行升序排序。To sort the array, the example defines a generic ScoreComparer class that implements the IComparer interface and sorts the Tuple<T1,T2> objects in ascending order by the value of their second component rather than their first component. 请注意, 该示例不会直接调用IStructuralComparable.CompareTo方法。Note that the example does not directly call the IStructuralComparable.CompareTo method. 此方法由Array.Sort(Array, IComparer)方法为数组中的每个元素隐式调用。This method is called implicitly by the Array.Sort(Array, IComparer) method for each element in the array.

using System;
using System.Collections;
using System.Collections.Generic;

public class ScoreComparer<T1, T2> : IComparer
{
   public int Compare(object x, object y)
   {
      Tuple<T1, T2> tX = x as Tuple<T1,T2>;
      if (tX == null)
      { 
         return 0;
      }   
      else
      {
         Tuple<T1, T2> tY = y as Tuple<T1, T2>;
         return Comparer<T2>.Default.Compare(tX.Item2, tY.Item2);             
      }
   }
}

public class Example
{
   public static void Main()
   {
      Tuple<string, Nullable<int>>[] scores = 
                    { new Tuple<string, Nullable<int>>("Jack", 78),
                      new Tuple<string, Nullable<int>>("Abbey", 92), 
                      new Tuple<string, Nullable<int>>("Dave", 88),
                      new Tuple<string, Nullable<int>>("Sam", 91), 
                      new Tuple<string, Nullable<int>>("Ed", null),
                      new Tuple<string, Nullable<int>>("Penelope", 82),
                      new Tuple<string, Nullable<int>>("Linda", 99),
                      new Tuple<string, Nullable<int>>("Judith", 84) };

      Console.WriteLine("The values in unsorted order:");
      foreach (var score in scores)
         Console.WriteLine(score.ToString());

      Console.WriteLine();

      Array.Sort(scores, new ScoreComparer<string, Nullable<int>>());

      Console.WriteLine("The values in sorted order:");
      foreach (var score in scores)
         Console.WriteLine(score.ToString());
   }
}
// The example displays the following output;
//       The values in unsorted order:
//       (Jack, 78)
//       (Abbey, 92)
//       (Dave, 88)
//       (Sam, 91)
//       (Ed, )
//       (Penelope, 82)
//       (Linda, 99)
//       (Judith, 84)
//       
//       The values in sorted order:
//       (Ed, )
//       (Jack, 78)
//       (Penelope, 82)
//       (Judith, 84)
//       (Dave, 88)
//       (Sam, 91)
//       (Abbey, 92)
//       (Linda, 99)
Imports System.Collections
Imports System.Collections.Generic

Public Class ScoreComparer(Of T1, T2) : Implements IComparer
   Public Function Compare(x As Object, y As Object) As Integer _
                   Implements IComparer.Compare
      Dim tX As Tuple(Of T1, T2) = TryCast(x, Tuple(Of T1, T2))
      If tX Is Nothing Then
         Return 0
      Else
         Dim tY As Tuple(Of T1, T2) = DirectCast(y, Tuple(Of T1, T2))
         Return Comparer(Of T2).Default.Compare(tx.Item2, tY.Item2)             
      End If
   End Function
End Class

Module Example
   Public Sub Main()
      Dim scores() As Tuple(Of String, Nullable(Of Integer)) = 
                      { New Tuple(Of String, Nullable(Of Integer))("Jack", 78),
                        New Tuple(Of String, Nullable(Of Integer))("Abbey", 92), 
                        New Tuple(Of String, Nullable(Of Integer))("Dave", 88),
                        New Tuple(Of String, Nullable(Of Integer))("Sam", 91), 
                        New Tuple(Of String, Nullable(Of Integer))("Ed", Nothing),
                        New Tuple(Of String, Nullable(Of Integer))("Penelope", 82),
                        New Tuple(Of String, Nullable(Of Integer))("Linda", 99),
                        New Tuple(Of String, Nullable(Of Integer))("Judith", 84) }

      Console.WriteLine("The values in unsorted order:")
      For Each score In scores
         Console.WriteLine(score.ToString())
      Next
      Console.WriteLine()

      Array.Sort(scores, New ScoreComparer(Of String, Nullable(Of Integer))())

      Console.WriteLine("The values in sorted order:")
      For Each score In scores
         Console.WriteLine(score.ToString())
      Next
   End Sub
End Module
' The example displays the following output;
'       The values in unsorted order:
'       (Jack, 78)
'       (Abbey, 92)
'       (Dave, 88)
'       (Sam, 91)
'       (Ed, )
'       (Penelope, 82)
'       (Linda, 99)
'       (Judith, 84)
'       
'       The values in sorted order:
'       (Ed, )
'       (Jack, 78)
'       (Penelope, 82)
'       (Judith, 84)
'       (Dave, 88)
'       (Sam, 91)
'       (Abbey, 92)
'       (Linda, 99)

注解

此成员是显式接口成员的实现。This member is an explicit interface member implementation. 它只能在 Tuple<T1,T2> 实例被强制转换为 IStructuralComparable 接口时使用。It can be used only when the Tuple<T1,T2> instance is cast to an IStructuralComparable interface.

尽管可以直接调用此方法, 但它最常见的方法是包含IComparer参数的集合排序方法, 以对集合的成员进行排序。Although this method can be called directly, it is most commonly called by collection sorting methods that include IComparer parameters to order the members of a collection. 例如, 它Array.Sort(Array, IComparer)由方法Add和使用SortedList.SortedList(IComparer)构造函数实例化的SortedList对象的方法调用。For example, it is called by the Array.Sort(Array, IComparer) method and the Add method of a SortedList object that is instantiated by using the SortedList.SortedList(IComparer) constructor.

注意

IStructuralComparable.CompareTo方法旨在用于排序操作。The IStructuralComparable.CompareTo method is intended for use in sorting operations. 如果比较的主要目的是确定两个对象是否相等, 则不应使用此方法。It should not be used when the primary purpose of a comparison is to determine whether two objects are equal. 若要确定两个对象是否相等, 请IStructuralEquatable.Equals调用方法。To determine whether two objects are equal, call the IStructuralEquatable.Equals method.

适用于

另请参阅