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

定义

使用指定的比较器将当前的 Tuple<T1> 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> 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 Object Object

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

comparer
IComparer IComparer 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 描述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> 对象。other is not a Tuple<T1> object.

示例

下面的示例定义一个名为的泛型类DescendingComparer实现IComparer<T>接口。The following example defines a generic class named DescendingComparer that implements the IComparer<T> interface. DescendingComparer 在通过反转特定类型的默认比较器返回的值而不按升序排列降序对象进行排序。DescendingComparer sorts objects in descending rather than ascending order by reversing the value returned by the default comparer for a particular type. 实例的泛型DescendingComparer然后将类传递给Array.Sort(Array, IComparer)方法进行排序的数组Tuple<T1>降序排序的对象。An instance of the generic DescendingComparer class is then passed to the Array.Sort(Array, IComparer) method to sort an array of Tuple<T1> objects in descending order. 请注意,该示例不直接调用IStructuralComparable.CompareTo方法。Note that the example does not directly call the IStructuralComparable.CompareTo method. 隐式调用此方法Array.Sort(Array, IComparer)数组中的每个元素的方法。This method is called implicitly by the Array.Sort(Array, IComparer) method for each element in the array.

using System;
using System.Collections.Generic;

public class DescendingComparer<T> : IComparer<T>
{
    public int Compare(T x, T y) 
    {
        return -1 * Comparer<T>.Default.Compare(x, y);
    }
}

class CompareTo2
{
   static void Main()
   {
       Tuple<Double>[] values = { Tuple.Create(13.54),
                                  Tuple.Create(Double.NaN),
                                  Tuple.Create(-189.42993),
                                  Tuple.Create(Double.PositiveInfinity),
                                  Tuple.Create(Double.Epsilon),
                                  Tuple.Create(1.934E-17),
                                  Tuple.Create(Double.NegativeInfinity),
                                  Tuple.Create(-0.000000000003588),
                                  null };
       Console.WriteLine("The values in unsorted order:");
       foreach (var value in values)
           if (value != null)
               Console.WriteLine("   {0}", value.Item1);
           else
               Console.WriteLine("   <null>");
       Console.WriteLine();

       Array.Sort(values, new DescendingComparer<Tuple<Double>>());

       Console.WriteLine("The values sorted in descending order:");
       foreach (var value in values)
           if (value != null)
               Console.WriteLine("   {0}", value.Item1);
           else
               Console.WriteLine("   <null>");
    }
}
// The example displays the following output:
//      The values in unsorted order:
//         13.54
//         NaN
//         -189.42993
//         Infinity
//         4.94065645841247E-324
//         1.934E-17
//         -Infinity
//         -3.588E-12
//
//      The values sorted in descending order:
//         Infinity
//         13.54
//         1.934E-17
//         4.94065645841247E-324
//         -3.588E-12
//         -189.42993
//         -Infinity
//         NaN
Imports System.Collections.Generic

Public Class DescendingComparer(Of T) : Implements IComparer(Of T)
    Public Function Compare(ByVal x As T, ByVal y As T) As Integer Implements IComparer(Of T).Compare
        Return -1 * Comparer(Of T).Default.Compare(x, y)
    End Function
End Class

Module Example
    Sub Main()
        Dim values() = { Tuple.Create(13.54),
                         Tuple.Create(Double.NaN),
                         Tuple.Create(-189.42993),
                         Tuple.Create(Double.PositiveInfinity),
                         Tuple.Create(Double.Epsilon),
                         Tuple.Create(1.934E-17),
                         Tuple.Create(Double.NegativeInfinity),
                         Tuple.Create(-0.000000000003588),
                         Nothing}

        Console.WriteLine("The values in unsorted order:")
        For Each value As Tuple(Of Double) In values
            If value IsNot Nothing Then
                Console.WriteLine("   {0}", value.Item1)
            Else
                Console.WriteLine("   <null>")
            End If
        Next
        Console.WriteLine()

        Array.Sort(values, New DescendingComparer(Of Tuple(Of Double)))

        Console.WriteLine("The values sorted in descending order:")
        For Each value As Tuple(Of Double) In values
            If value IsNot Nothing Then
                Console.WriteLine("   {0}", value.Item1)
            Else
                Console.WriteLine("   <null>")
            End If
        Next
    End Sub
End Module
' The example displays the following output:
'      The values in unsorted order:
'         13.54
'         NaN
'         -189.42993
'         Infinity
'         4.94065645841247E-324
'         1.934E-17
'         -Infinity
'         -3.588E-12
'
'      The values sorted in descending order:
'         Infinity
'         13.54
'         1.934E-17
'         4.94065645841247E-324
'         -3.588E-12
'         -189.42993
'         -Infinity
'         NaN

注解

虽然可以直接调用此方法,通常称为集合排序方法,包括通过IComparer参数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,调用Array.Sort(Array, IComparer)方法和Add方法SortedList对象,它通过使用实例化SortedList.SortedList(IComparer)构造函数。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方法应在排序操作中使用。The IStructuralComparable.CompareTo method is intended for use in sorting operations. 它不应比较的主要目的在于确定两个对象是否相等。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,调用IStructuralEquatable.Equals方法。To determine whether two objects are equal, call the IStructuralEquatable.Equals method.

适用于

另请参阅