Comparer<T> Comparer<T> Comparer<T> Comparer<T> Class

定義

IComparer<T> ジェネリック インターフェイスの実装のための基本クラスを提供します。Provides a base class for implementations of the IComparer<T> generic interface.

generic <typename T>
public ref class Comparer abstract : System::Collections::Generic::IComparer<T>, System::Collections::IComparer
[System.Serializable]
public abstract class Comparer<T> : System.Collections.Generic.IComparer<T>, System.Collections.IComparer
type Comparer<'T> = class
    interface IComparer
    interface IComparer<'T>
Public MustInherit Class Comparer(Of T)
Implements IComparer, IComparer(Of T)

型パラメーター

T

比較するオブジェクトの型。The type of objects to compare.

継承
Comparer<T>Comparer<T>Comparer<T>Comparer<T>
属性
実装

次の例では、派生クラスでBoxLengthFirstから、Comparer<T>クラス。The following example derives a class, BoxLengthFirst, from the Comparer<T> class. この比較演算子は、型の 2 つのオブジェクトを比較します。Boxします。This comparer compares two objects of type Box. これは、並べ替えて最初の長さによって、高さ、られ、続いて幅。It sorts them first by length, then by height, and then by width. Boxクラスが実装する、 IComparable<T> 2 つの既定の比較を制御するインターフェイスBoxオブジェクト。The Box class implements the IComparable<T> interface to control the default comparison between two Box objects. この既定の実装は、高さによって、長さ、られ、続いて幅は最初に並べ替えられます。This default implementation sorts first by height, then by length, and then by width. 一覧を並べ替えることで、2 つの比較の違いの例を示しますBoxオブジェクトを最初を使用して、BoxLengthFirst比較子、および既定の比較子を使用します。The example shows the differences between the two comparisons by sorting a list of Box objects first by using the BoxLengthFirst comparer and then by using the default comparer.

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

class Program
{
    static void Main(string[] args)
    {
        List<Box> Boxes = new List<Box>();
        Boxes.Add(new Box(4, 20, 14));
        Boxes.Add(new Box(12, 12, 12));
        Boxes.Add(new Box(8, 20, 10));
        Boxes.Add(new Box(6, 10, 2));
        Boxes.Add(new Box(2, 8, 4));
        Boxes.Add(new Box(2, 6, 8));
        Boxes.Add(new Box(4, 12, 20));
        Boxes.Add(new Box(18, 10, 4));
        Boxes.Add(new Box(24, 4, 18));
        Boxes.Add(new Box(10, 4, 16));
        Boxes.Add(new Box(10, 2, 10));
        Boxes.Add(new Box(6, 18, 2));
        Boxes.Add(new Box(8, 12, 4));
        Boxes.Add(new Box(12, 10, 8));
        Boxes.Add(new Box(14, 6, 6));
        Boxes.Add(new Box(16, 6, 16));
        Boxes.Add(new Box(2, 8, 12));
        Boxes.Add(new Box(4, 24, 8));
        Boxes.Add(new Box(8, 6, 20));
        Boxes.Add(new Box(18, 18, 12));

        // Sort by an Comparer<T> implementation that sorts
        // first by the length.
        Boxes.Sort(new BoxLengthFirst());

        Console.WriteLine("H - L - W");
        Console.WriteLine("==========");
        foreach (Box bx in Boxes)
        {
            Console.WriteLine("{0}\t{1}\t{2}",
                bx.Height.ToString(), bx.Length.ToString(), 
                bx.Width.ToString());
        }

        Console.WriteLine();
        Console.WriteLine("H - L - W"); 
        Console.WriteLine("==========");

        // Get the default comparer that 
        // sorts first by the height.
        Comparer<Box> defComp = Comparer<Box>.Default;

        // Calling Boxes.Sort() with no parameter
        // is the same as calling Boxs.Sort(defComp)
        // because they are both using the default comparer.
        Boxes.Sort();

        foreach (Box bx in Boxes)
        {
            Console.WriteLine("{0}\t{1}\t{2}",
                bx.Height.ToString(), bx.Length.ToString(), 
                bx.Width.ToString());
        }


        // This explicit interface implementation
        // compares first by the length.
        // Returns -1 because the length of BoxA
        // is less than the length of BoxB.
        BoxLengthFirst LengthFirst = new BoxLengthFirst(); 

        Comparer<Box> bc = (Comparer<Box>) LengthFirst;

        Box BoxA = new Box(2, 6, 8);
        Box BoxB = new Box(10, 12, 14);
        int x = LengthFirst.Compare(BoxA, BoxB);
        Console.WriteLine();
        Console.WriteLine(x.ToString());

    

    }

}

public class BoxLengthFirst : Comparer<Box> 
{
    // Compares by Length, Height, and Width.
    public override int Compare(Box x, Box y)
    {
        if (x.Length.CompareTo(y.Length) != 0)
        {
            return x.Length.CompareTo(y.Length);
        }
        else if (x.Height.CompareTo(y.Height) != 0)
        {
            return x.Height.CompareTo(y.Height);
        }
        else if (x.Width.CompareTo(y.Width) != 0)
        {
            return x.Width.CompareTo(y.Width);
        }
        else
        {
            return 0;
        }
    }

}

// This class is not demonstrated in the Main method
// and is provided only to show how to implement
// the interface. It is recommended to derive
// from Comparer<T> instead of implementing IComparer<T>.
public class BoxComp : IComparer<Box>
{
    // Compares by Height, Length, and Width.
    public int Compare(Box x, Box y)
    {
        if (x.Height.CompareTo(y.Height) != 0)
        {
            return x.Height.CompareTo(y.Height);
        }
        else if (x.Length.CompareTo(y.Length) != 0)
        {
            return x.Length.CompareTo(y.Length);
        }
        else if (x.Width.CompareTo(y.Width) != 0)
        {
            return x.Width.CompareTo(y.Width);
        }
        else
        {
            return 0;
        }
    }
}

public class Box : IComparable<Box>
{

    public Box(int h, int l, int w)
    {
        this.Height = h;
        this.Length = l;
        this.Width = w;
    }
    public int Height { get; private set; }
    public int Length { get; private set; }
    public int Width { get; private set; }

    public int CompareTo(Box other)
    {
        // Compares Height, Length, and Width.
        if (this.Height.CompareTo(other.Height) != 0)
        {
            return this.Height.CompareTo(other.Height);
        }
        else if (this.Length.CompareTo(other.Length) != 0)
        {
            return this.Length.CompareTo(other.Length);
        }
        else if (this.Width.CompareTo(other.Width) != 0)
        {
            return this.Width.CompareTo(other.Width);
        }
        else
        {
            return 0;
        }
    }

}

Imports System.Collections.Generic

Friend Class Program
	Shared Sub Main(ByVal args() As String)
		Dim Boxes As New List(Of Box)()
		Boxes.Add(New Box(4, 20, 14))
		Boxes.Add(New Box(12, 12, 12))
		Boxes.Add(New Box(8, 20, 10))
		Boxes.Add(New Box(6, 10, 2))
		Boxes.Add(New Box(2, 8, 4))
		Boxes.Add(New Box(2, 6, 8))
		Boxes.Add(New Box(4, 12, 20))
		Boxes.Add(New Box(18, 10, 4))
		Boxes.Add(New Box(24, 4, 18))
		Boxes.Add(New Box(10, 4, 16))
		Boxes.Add(New Box(10, 2, 10))
		Boxes.Add(New Box(6, 18, 2))
		Boxes.Add(New Box(8, 12, 4))
		Boxes.Add(New Box(12, 10, 8))
		Boxes.Add(New Box(14, 6, 6))
		Boxes.Add(New Box(16, 6, 16))
		Boxes.Add(New Box(2, 8, 12))
		Boxes.Add(New Box(4, 24, 8))
		Boxes.Add(New Box(8, 6, 20))
		Boxes.Add(New Box(18, 18, 12))

		' Sort by an Comparer<T> implementation that sorts
		' first by the length.
		Boxes.Sort(New BoxLengthFirst())

		Console.WriteLine("H - L - W")
		Console.WriteLine("==========")
		For Each bx As Box In Boxes
            Console.WriteLine("{0}" & vbTab & "{1}" & vbTab & "{2}", _
                              bx.Height.ToString(), bx.Length.ToString(), _
                              bx.Width.ToString())
		Next bx

		Console.WriteLine()
		Console.WriteLine("H - L - W")
		Console.WriteLine("==========")

		' Get the default comparer that 
		' sorts first by the height.
		Dim defComp As Comparer(Of Box) = Comparer(Of Box).Default

		' Calling Boxes.Sort() with no parameter
		' is the same as calling Boxs.Sort(defComp)
		' because they are both using the default comparer.
		Boxes.Sort()

		For Each bx As Box In Boxes
            Console.WriteLine("{0}" & vbTab & "{1}" & vbTab & "{2}", _
                              bx.Height.ToString(), _
                              bx.Length.ToString(), _
                              bx.Width.ToString())
		Next bx


		' This explicit interface implementation
		' compares first by the length.
		' Returns -1 because the length of BoxA
		' is less than the length of BoxB.
		Dim LengthFirst As New BoxLengthFirst()

		Dim bc As Comparer(Of Box) = CType(LengthFirst, Comparer(Of Box))

		Dim BoxA As New Box(2, 6, 8)
		Dim BoxB As New Box(10, 12, 14)
		Dim x As Integer = LengthFirst.Compare(BoxA, BoxB)
		Console.WriteLine()
		Console.WriteLine(x.ToString())



	End Sub

End Class

Public Class BoxLengthFirst
	Inherits Comparer(Of Box)
	' Compares by Length, Height, and Width.
	Public Overrides Function Compare(ByVal x As Box, ByVal y As Box) As Integer
		If x.Length.CompareTo(y.Length) <> 0 Then
			Return x.Length.CompareTo(y.Length)
		ElseIf x.Height.CompareTo(y.Height) <> 0 Then
			Return x.Height.CompareTo(y.Height)
		ElseIf x.Width.CompareTo(y.Width) <> 0 Then
			Return x.Width.CompareTo(y.Width)
		Else
			Return 0
		End If
	End Function

End Class

' This class is not demonstrated in the Main method
' and is provided only to show how to implement
' the interface. It is recommended to derive
' from Comparer<T> instead of implementing IComparer<T>.
Public Class BoxComp
	Implements IComparer(Of Box)
	' Compares by Height, Length, and Width.
    Public Function Compare(ByVal x As Box, ByVal y As Box) As Integer Implements _
                                                IComparer(Of Box).Compare
        If x.Height.CompareTo(y.Height) <> 0 Then
            Return x.Height.CompareTo(y.Height)
        ElseIf x.Length.CompareTo(y.Length) <> 0 Then
            Return x.Length.CompareTo(y.Length)
        ElseIf x.Width.CompareTo(y.Width) <> 0 Then
            Return x.Width.CompareTo(y.Width)
        Else
            Return 0
        End If
    End Function
End Class

Public Class Box
	Implements IComparable(Of Box)

	Public Sub New(ByVal h As Integer, ByVal l As Integer, ByVal w As Integer)
		Me.Height = h
		Me.Length = l
		Me.Width = w
	End Sub
	Private privateHeight As Integer
	Public Property Height() As Integer
		Get
			Return privateHeight
		End Get
		Private Set(ByVal value As Integer)
			privateHeight = value
		End Set
	End Property
	Private privateLength As Integer
	Public Property Length() As Integer
		Get
			Return privateLength
		End Get
		Private Set(ByVal value As Integer)
			privateLength = value
		End Set
	End Property
	Private privateWidth As Integer
	Public Property Width() As Integer
		Get
			Return privateWidth
		End Get
		Private Set(ByVal value As Integer)
			privateWidth = value
		End Set
	End Property

    Public Function CompareTo(ByVal other As Box) As Integer _
                        Implements IComparable(Of Box).CompareTo
        ' Compares Height, Length, and Width.
        If Me.Height.CompareTo(other.Height) <> 0 Then
            Return Me.Height.CompareTo(other.Height)
        ElseIf Me.Length.CompareTo(other.Length) <> 0 Then
            Return Me.Length.CompareTo(other.Length)
        ElseIf Me.Width.CompareTo(other.Width) <> 0 Then
            Return Me.Width.CompareTo(other.Width)
        Else
            Return 0
        End If
    End Function

End Class

注釈

カスタム実装を提供するには、このクラスから派生、IComparer<T>コレクション クラスで使用するためのインターフェイスなど、SortedList<TKey,TValue>SortedDictionary<TKey,TValue>ジェネリック クラスです。Derive from this class to provide a custom implementation of the IComparer<T> interface for use with collection classes such as the SortedList<TKey,TValue> and SortedDictionary<TKey,TValue> generic classes.

派生する間の差、Comparer<T>クラスと実装、System.IComparableインターフェイスは、次のようにします。The difference between deriving from the Comparer<T> class and implementing the System.IComparable interface is as follows:

  • 指定する方法、既定では、2 つのオブジェクトを比較する必要があります、実装、System.IComparableクラスのインターフェイス。To specify how two objects should be compared by default, implement the System.IComparable interface in your class. これにより、並べ替え操作が指定した既定の比較コードを使用します。This ensures that sort operations will use the default comparison code that you provided.

  • 派生する既定の比較子の代わりに使用する比較子を定義する、Comparer<T>クラス。To define a comparer to use instead of the default comparer, derive from the Comparer<T> class. この比較演算子は、パラメーターとしての比較子を取得する並べ替え操作で使用できます。You can then use this comparer in sort operations that take a comparer as a parameter.

によって返されるオブジェクト、Defaultプロパティで使用、System.IComparable<T>ジェネリック インターフェイス (IComparable<T> c# でIComparable(Of T)Visual Basic で) 2 つのオブジェクトを比較します。The object returned by the Default property uses the System.IComparable<T> generic interface (IComparable<T> in C#, IComparable(Of T) in Visual Basic) to compare two objects. 場合型Tを実装しません、System.IComparable<T>ジェネリック インターフェイスをDefaultプロパティが返す、Comparer<T>を使用して、System.IComparableインターフェイス。If type T does not implement the System.IComparable<T> generic interface, the Default property returns a Comparer<T> that uses the System.IComparable interface.

注意 (継承者)

Compare(T, T) System.Collections.Generic.EqualityComparer`1.Equals(\`0,\`0)カルチャの区別および大文字小文字の区別に関して動作が異なる場合があります。 System.Collections.Generic.Comparer`1.Compare(`0,\`0) and System.Collections.Generic.EqualityComparer`1.Equals(`0,\`0) may behave differently in terms of culture-sensitivity and case-sensitivity.

文字列の比較、StringComparerクラスがよりも推奨比較子<文字列>します。For string comparisons, the StringComparer class is recommended over Comparer<String>. プロパティ、StringComparerクラスは、カルチャの区別および大文字小文字の区別のさまざまな組み合わせで文字列比較を実行する定義済みのインスタンスを返します。Properties of the StringComparer class return predefined instances that perform string comparisons with different combinations of culture-sensitivity and case-sensitivity. 大文字小文字の区別とカルチャの区別は、同じメンバーの間で一貫性のあるStringComparerインスタンス。The case-sensitivity and culture-sensitivity are consistent among the members of the same StringComparer instance.

カルチャ固有の比較の詳細については、次を参照してください。、System.Globalization名前空間とグローバリゼーションとローカリゼーションします。For more information on culture-specific comparisons, see the System.Globalization namespace and Globalization and Localization.

コンストラクター

Comparer<T>() Comparer<T>() Comparer<T>() Comparer<T>()

Comparer<T> クラスの新しいインスタンスを初期化します。Initializes a new instance of the Comparer<T> class.

プロパティ

Default Default Default Default

汎用引数で指定された型に対して、既定の並べ替え順序比較子を返します。Returns a default sort order comparer for the type specified by the generic argument.

メソッド

Compare(T, T) Compare(T, T) Compare(T, T) Compare(T, T)

派生クラスでオーバーライドされると、同じ型の 2 つのオブジェクトに対する比較を実行し、一方のオブジェクトが他方よりも小さいか、等しいか、大きいかを示す値を返します。When overridden in a derived class, performs a comparison of two objects of the same type and returns a value indicating whether one object is less than, equal to, or greater than the other.

Create(Comparison<T>) Create(Comparison<T>) Create(Comparison<T>) Create(Comparison<T>)

指定した比較を使用して比較子を作成します。Creates a comparer by using the specified comparison.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

指定したオブジェクトが、現在のオブジェクトと等しいかどうかを判断します。Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

既定のハッシュ関数として機能します。Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

現在のインスタンスの Type を取得します。Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

現在の Object の簡易コピーを作成します。Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

現在のオブジェクトを表す文字列を返します。Returns a string that represents the current object.

(Inherited from Object)

明示的なインターフェイスの実装

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

2 つのオブジェクトを比較して、一方が他方より小さいか、同じか、または大きいかを示す値を返します。Compares two objects and returns a value indicating whether one is less than, equal to, or greater than the other.

適用対象

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