IStructuralComparable 介面

定義

支援集合物件的結構比較。Supports the structural comparison of collection objects.

public interface class IStructuralComparable
public interface IStructuralComparable
type IStructuralComparable = interface
Public Interface IStructuralComparable
衍生

範例

下列範例會建立Tuple<T1,T2,T3,T4,T5,T6>物件的陣列, 其中包含三個美國城市的人口資料 (從1960到 2000)。The following example creates an array of Tuple<T1,T2,T3,T4,T5,T6> objects that contains population data for three U.S. cities from 1960 to 2000. Sextuple 的第一個元件是城市名稱。The sextuple's first component is the city name. 其餘的五個元件代表從1960到2000的十年間隔擴展。The remaining five components represent the population at ten-year intervals from 1960 to 2000.

類別會提供可讓 sextuples 陣列依其任何一個元件排序的執行。IComparer PopulationComparerThe PopulationComparer class provides an IComparer implementation that allows the array of sextuples to be sorted by any one of its components. 在其「函式」 PopulationComparer中, 會提供兩個值給類別: 定義排序次序的元件位置, 以及指出是否應以遞增或遞減順序排序元組物件的布林值。Two values are provided to the PopulationComparer class in its constructor: the position of the component that defines the sort order, and a Boolean value that indicates whether the tuple objects should be sorted in ascending or descending order.

然後, 此範例會以未排序的順序顯示陣列中的專案, 然後依第三個元件 (1970 中的擴展) 加以排序並顯示它們, 然後依第六個元件 (2000 中的擴展) 加以排序, 然後顯示這些元素。The example then displays the elements in the array in unsorted order, sorts them by the third component (the population in 1970) and displays them, and then sorts them by the sixth component (the population in 2000) and displays them. 請注意, 此範例不會直接呼叫CompareTo方法。Note that the example does not directly call the CompareTo method. 方法會針對陣列中的每Sort(Array, IComparer)個元組物件, 隱含地由方法呼叫。The method is called implicitly by the Sort(Array, IComparer) method for each tuple object in the array.

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

public class PopulationComparer<T1, T2, T3, T4, T5, T6> : IComparer
{
   private int itemPosition;
   private int multiplier = -1;

   public PopulationComparer(int component) : this(component, true)
   { }

   public PopulationComparer(int component, bool descending)
   {
      if (! descending) multiplier = 1;

      if (component <= 0 || component > 6)
         throw new ArgumentException("The component argument is out of range.");

      itemPosition = component;
   }

   public int Compare(object x, object y)
   {
      var tX = x as Tuple<T1, T2, T3, T4, T5, T6>;
      if (tX == null)
      {
         return 0;
      }
      else
      {
         var tY = y as Tuple<T1, T2, T3, T4, T5, T6>;
         switch (itemPosition)
         {
            case 1:
               return Comparer<T1>.Default.Compare(tX.Item1, tY.Item1) * multiplier;
            case 2:
               return Comparer<T2>.Default.Compare(tX.Item2, tY.Item2) * multiplier;
            case 3:
               return Comparer<T3>.Default.Compare(tX.Item3, tY.Item3) * multiplier;
            case 4:
               return Comparer<T4>.Default.Compare(tX.Item4, tY.Item4) * multiplier;
            case 5:
               return Comparer<T5>.Default.Compare(tX.Item5, tY.Item5) * multiplier;
            case 6:
               return Comparer<T6>.Default.Compare(tX.Item6, tY.Item6) * multiplier;
            default:
               return Comparer<T1>.Default.Compare(tX.Item1, tY.Item1) * multiplier;
         }
      }
   }
}

public class Example
{
   public static void Main()
   {
      // Create array of sextuple with population data for three U.S.
      // cities, 1960-2000.
      Tuple<string, int, int, int, int, int>[] cities =
           { Tuple.Create("Los Angeles", 2479015, 2816061, 2966850, 3485398, 3694820),
             Tuple.Create("New York", 7781984, 7894862, 7071639, 7322564, 8008278),
             Tuple.Create("Chicago", 3550904, 3366957, 3005072, 2783726, 2896016) };

      // Display array in unsorted order.
      Console.WriteLine("In unsorted order:");
      foreach (var city in cities)
         Console.WriteLine(city.ToString());
      Console.WriteLine();

      Array.Sort(cities, new PopulationComparer<string, int, int, int, int, int>(3));

      // Display array in sorted order.
      Console.WriteLine("Sorted by population in 1970:");
      foreach (var city in cities)
         Console.WriteLine(city.ToString());
      Console.WriteLine();

      Array.Sort(cities, new PopulationComparer<string, int, int, int, int, int>(6));

      // Display array in sorted order.
      Console.WriteLine("Sorted by population in 2000:");
      foreach (var city in cities)
         Console.WriteLine(city.ToString());
   }
}
// The example displays the following output:
//    In unsorted order:
//    (Los Angeles, 2479015, 2816061, 2966850, 3485398, 3694820)
//    (New York, 7781984, 7894862, 7071639, 7322564, 8008278)
//    (Chicago, 3550904, 3366957, 3005072, 2783726, 2896016)
//    
//    Sorted by population in 1970:
//    (New York, 7781984, 7894862, 7071639, 7322564, 8008278)
//    (Chicago, 3550904, 3366957, 3005072, 2783726, 2896016)
//    (Los Angeles, 2479015, 2816061, 2966850, 3485398, 3694820)
//    
//    Sorted by population in 2000:
//    (New York, 7781984, 7894862, 7071639, 7322564, 8008278)
//    (Los Angeles, 2479015, 2816061, 2966850, 3485398, 3694820)
//    (Chicago, 3550904, 3366957, 3005072, 2783726, 2896016)
Imports System.Collections
Imports System.Collections.Generic

Public Class PopulationComparer(Of T1, T2, T3, T4, T5, T6) : Implements IComparer
   Private itemPosition As Integer
   Private multiplier As Integer = -1
      
   Public Sub New(component As Integer)
      Me.New(component, True)
   End Sub
   
   Public Sub New(component As Integer, descending As Boolean)
      If Not descending Then multiplier = 1
      
      If component <= 0 Or component > 6 Then 
         Throw New ArgumentException("The component argument is out of range.")
      End If
      itemPosition = component
   End Sub 
   
   Public Function Compare(x As Object, y As Object) As Integer _
                   Implements IComparer.Compare
 
      Dim tX = TryCast(x, Tuple(Of T1, T2, T3, T4, T5, T6))
      If tX Is Nothing Then
         Return 0
      Else
         Dim tY = DirectCast(y, Tuple(Of T1, T2, T3, T4, T5, T6))
         Select Case itemPosition
            Case 1
               Return Comparer(Of T1).Default.Compare(tX.Item1, tY.Item1) * multiplier
            Case 2
               Return Comparer(Of T2).Default.Compare(tX.Item2, tY.Item2) * multiplier
            Case 3
               Return Comparer(Of T3).Default.Compare(tX.Item3, tY.Item3) * multiplier
            Case 4
               Return Comparer(Of T4).Default.Compare(tX.Item4, tY.Item4) * multiplier
            Case 5
               Return Comparer(Of T5).Default.Compare(tX.Item5, tY.Item5) * multiplier
            Case 6
               Return Comparer(Of T6).Default.Compare(tX.Item6, tY.Item6) * multiplier
            ' This should never happen.
            Case Else
               Return 0
         End Select      
      End If
   End Function
End Class

Module Example
   Public Sub Main()
      ' Create array of sextuple with population data for three U.S. 
      ' cities, 1960-2000.
      Dim cities() = 
          { Tuple.Create("Los Angeles", 2479015, 2816061, 2966850, 3485398, 3694820),
            Tuple.Create("New York", 7781984, 7894862, 7071639, 7322564, 8008278),  
            Tuple.Create("Chicago", 3550904, 3366957, 3005072, 2783726, 2896016) } 
      
      ' Display array in unsorted order.
      Console.WriteLine("In unsorted order:")
      For Each city In cities
         Console.WriteLine(city.ToString())
      Next
      Console.WriteLine()
      
      Array.Sort(cities, New PopulationComparer(Of String, Integer, Integer, Integer, Integer, Integer)(3)) 
                           
      ' Display array in sorted order.
      Console.WriteLine("Sorted by population in 1970:")
      For Each city In cities
         Console.WriteLine(city.ToString())
      Next
      Console.WriteLine()
      
      Array.Sort(cities, New PopulationComparer(Of String, Integer, Integer, Integer, Integer, Integer)(6))
                           
      ' Display array in sorted order.
      Console.WriteLine("Sorted by population in 2000:")
      For Each city In cities
         Console.WriteLine(city.ToString())
      Next
   End Sub
End Module
' The example displays the following output:
'    In unsorted order:
'    (Los Angeles, 2479015, 2816061, 2966850, 3485398, 3694820)
'    (New York, 7781984, 7894862, 7071639, 7322564, 8008278)
'    (Chicago, 3550904, 3366957, 3005072, 2783726, 2896016)
'    
'    Sorted by population in 1970:
'    (New York, 7781984, 7894862, 7071639, 7322564, 8008278)
'    (Chicago, 3550904, 3366957, 3005072, 2783726, 2896016)
'    (Los Angeles, 2479015, 2816061, 2966850, 3485398, 3694820)
'    
'    Sorted by population in 2000:
'    (New York, 7781984, 7894862, 7071639, 7322564, 8008278)
'    (Los Angeles, 2479015, 2816061, 2966850, 3485398, 3694820)
'    (Chicago, 3550904, 3366957, 3005072, 2783726, 2896016)

備註

IStructuralComparable介面可讓您執行集合成員的自訂比較。The IStructuralComparable interface enables you to implement customized comparisons for collection members. 也就是說, 您可以明確地定義要在排序次序中的同一個位置, 在第二個集合物件之前、之後或發生的單一集合物件所代表的意義。That is, you can define precisely what it means for one collection object to precede, follow, or occur in the same position in the sort order as a second collection object. 然後, 您可以指定這個定義與接受IStructuralComparable介面的集合型別搭配使用。You can then specify that this definition be used with a collection type that accepts the IStructuralComparable interface.

介面具有單一成員, CompareTo它會判斷目前的集合物件是否小於、等於或大於排序次序中的第二個物件。The interface has a single member, CompareTo, which determines whether the current collection object is less than, equal to, or greater than a second object in the sort order. 目前實例中成員或專案與第二個物件的比較, 會由IComparer介面實執行, 其中包含自訂比較的定義。The actual comparison of the members or elements in the current instance with those in a second object is performed by an IComparer interface implementation, which contains the definition of your custom comparison.

注意

IStructuralComparable介面僅支援排序或排序的結構比較。The IStructuralComparable interface supports only structural comparisons for sorting or ordering. IStructuralEquatable介面支援結構相等的自訂比較。The IStructuralEquatable interface supports custom comparisons for structural equality.

.NET Framework 提供兩個預設的比較子。The .NET Framework provides two default comparers. StructuralComparisons.StructuralComparer屬性會傳回一個, 另一個則Comparer<T>.Default由屬性傳回。One is returned by the StructuralComparisons.StructuralComparer property; the other is returned by the Comparer<T>.Default property.

泛型元組類別 (Tuple<T1>Tuple<T1,T2>Tuple<T1,T2,T3>等) 和Array類別會提供介面的明確實作為IStructuralComparableThe generic tuple classes (Tuple<T1>, Tuple<T1,T2>, Tuple<T1,T2,T3>, and so on) and the Array class provide explicit implementations of the IStructuralComparable interface. 藉由轉換 ( C#在中) 或將陣列或元組的目前實例轉換 (Visual Basic) 為IStructuralComparable介面值, 並將IComparer您的實作為引數CompareTo提供給方法, 您可以定義自訂排序次序適用于陣列或集合。By casting (in C#) or converting (in Visual Basic) the current instance of an array or tuple to an IStructuralComparable interface value and providing your IComparer implementation as an argument to the CompareTo method, you can define a custom sort order for the array or collection. 不過, 在大部分的情況下CompareTo , 您不會直接呼叫方法。However, you do not call the CompareTo method directly in most cases. 相反地CompareTo Sort(Array, IComparer), 方法是藉由排序方法 (例如) 來呼叫。Instead, the CompareTo method is called by sorting methods such as Sort(Array, IComparer). 在此情況下, 您會IComparer定義您的實作為, 並將其當做引數傳遞至排序方法或集合物件的類別檢查器。In this case, you define your IComparer implementation and pass it as an argument to a sorting method or collection object's class constructor. CompareTo集合進行排序時, 會自動呼叫具有自訂比較子的方法。The CompareTo method with your custom comparer is then called automatically whenever the collection is sorted.

方法

CompareTo(Object, IComparer)

判斷目前的集合物件在排序次序中位於另一個物件之前、相同位置或之後。Determines whether the current collection object precedes, occurs in the same position as, or follows another object in the sort order.

適用於

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