StringComparer Clase

Definición

public ref class StringComparer abstract : System::Collections::Generic::IComparer<System::String ^>, System::Collections::Generic::IEqualityComparer<System::String ^>, System::Collections::IComparer, System::Collections::IEqualityComparer

public abstract class StringComparer : System.Collections.Generic.IComparer<string>, System.Collections.Generic.IEqualityComparer<string>, System.Collections.IComparer, System.Collections.IEqualityComparer

[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public abstract class StringComparer : System.Collections.Generic.IComparer<string>, System.Collections.Generic.IEqualityComparer<string>, System.Collections.IComparer, System.Collections.IEqualityComparer

type StringComparer = class
    interface IComparer<string>
    interface IEqualityComparer<string>
    interface IComparer
    interface IEqualityComparer

[<System.Runtime.InteropServices.ComVisible(true)>]
[<System.Serializable>]
type StringComparer = class
    interface IComparer
    interface IEqualityComparer
    interface IComparer<string>
    interface IEqualityComparer<string>

Public MustInherit Class StringComparer
Implements IComparer, IComparer(Of String), IEqualityComparer, IEqualityComparer(Of String)

Herencia

Object

StringComparer

Atributos

ComVisibleAttribute SerializableAttribute

Implementaciones

IComparer<String> IEqualityComparer<String> IComparer IEqualityComparer

Ejemplos

En el ejemplo siguiente se muestran las propiedades y el Create método de la StringComparer clase . En el ejemplo se muestra cómo los diferentes StringComparer objetos ordenan tres versiones de la letra latina I.

// This example demonstrates members of the 
// System.StringComparer class.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.Threading;

class Sample 
{
    public static void Main() 
    {
        // Create a list of string.
        List<string> list = new List<string>();

        // Get the tr-TR (Turkish-Turkey) culture.
        CultureInfo turkish = new CultureInfo("tr-TR");

        // Get the culture that is associated with the current thread.
        CultureInfo thisCulture = Thread.CurrentThread.CurrentCulture;

        // Get the standard StringComparers.
        StringComparer invCmp =   StringComparer.InvariantCulture;
        StringComparer invICCmp = StringComparer.InvariantCultureIgnoreCase;
        StringComparer currCmp = StringComparer.CurrentCulture;
        StringComparer currICCmp = StringComparer.CurrentCultureIgnoreCase;
        StringComparer ordCmp = StringComparer.Ordinal;
        StringComparer ordICCmp = StringComparer.OrdinalIgnoreCase;

        // Create a StringComparer that uses the Turkish culture and ignores case.
        StringComparer turkICComp = StringComparer.Create(turkish, true);

        // Define three strings consisting of different versions of the letter I.
        // LATIN CAPITAL LETTER I (U+0049)
        string capitalLetterI = "I";  

        // LATIN SMALL LETTER I (U+0069)
        string smallLetterI   = "i";

        // LATIN SMALL LETTER DOTLESS I (U+0131)
        string smallLetterDotlessI = "\u0131";

        // Add the three strings to the list.
        list.Add(capitalLetterI);
        list.Add(smallLetterI);
        list.Add(smallLetterDotlessI);

        // Display the original list order.
        Display(list, "The original order of the list entries...");

        // Sort the list using the invariant culture.
        list.Sort(invCmp);
        Display(list, "Invariant culture...");
        list.Sort(invICCmp);
        Display(list, "Invariant culture, ignore case...");

        // Sort the list using the current culture.
        Console.WriteLine("The current culture is \"{0}\".", thisCulture.Name);
        list.Sort(currCmp);
        Display(list, "Current culture...");
        list.Sort(currICCmp);
        Display(list, "Current culture, ignore case...");

        // Sort the list using the ordinal value of the character code points.
        list.Sort(ordCmp);
        Display(list, "Ordinal...");
        list.Sort(ordICCmp);
        Display(list, "Ordinal, ignore case...");

        // Sort the list using the Turkish culture, which treats LATIN SMALL LETTER 
        // DOTLESS I differently than LATIN SMALL LETTER I.
        list.Sort(turkICComp);
        Display(list, "Turkish culture, ignore case...");
    }

    public static void Display(List<string> lst, string title)
    {
        Char c;
        int  codePoint;
        Console.WriteLine(title);
        foreach (string s in lst)
        {
            c = s[0];
            codePoint = Convert.ToInt32(c);
            Console.WriteLine("0x{0:x}", codePoint); 
        }
        Console.WriteLine();
    }
}
/*
This code example produces the following results:

The original order of the list entries...
0x49
0x69
0x131

Invariant culture...
0x69
0x49
0x131

Invariant culture, ignore case...
0x49
0x69
0x131

The current culture is "en-US".
Current culture...
0x69
0x49
0x131

Current culture, ignore case...
0x49
0x69
0x131

Ordinal...
0x49
0x69
0x131

Ordinal, ignore case...
0x69
0x49
0x131

Turkish culture, ignore case...
0x131
0x49
0x69

*/

// This example demonstrates members of the 
// System.StringComparer class.

open System
open System.Globalization
open System.Threading

let display (lst: ResizeArray<string>) title =
    printfn $"%s{title}"
    for s in lst do
        let c = s[0]
        let codePoint = Convert.ToInt32 c
        printfn $"0x{codePoint:x}"
    printfn ""

// Create a list of string.
let list = ResizeArray()

// Get the tr-TR (Turkish-Turkey) culture.
let turkish = CultureInfo "tr-TR"

// Get the culture that is associated with the current thread.
let thisCulture = Thread.CurrentThread.CurrentCulture

// Get the standard StringComparers.
let invCmp =   StringComparer.InvariantCulture
let invICCmp = StringComparer.InvariantCultureIgnoreCase
let currCmp = StringComparer.CurrentCulture
let currICCmp = StringComparer.CurrentCultureIgnoreCase
let ordCmp = StringComparer.Ordinal
let ordICCmp = StringComparer.OrdinalIgnoreCase

// Create a StringComparer that uses the Turkish culture and ignores case.
let turkICComp = StringComparer.Create(turkish, true)

// Define three strings consisting of different versions of the letter I.
// LATIN CAPITAL LETTER I (U+0049)
let capitalLetterI = "I"  

// LATIN SMALL LETTER I (U+0069)
let smallLetterI   = "i"

// LATIN SMALL LETTER DOTLESS I (U+0131)
let smallLetterDotlessI = "\u0131"

// Add the three strings to the list.
list.Add capitalLetterI
list.Add smallLetterI
list.Add smallLetterDotlessI

// Display the original list order.
display list "The original order of the list entries..."

// Sort the list using the invariant culture.
list.Sort invCmp
display list "Invariant culture..."
list.Sort invICCmp
display list "Invariant culture, ignore case..."

// Sort the list using the current culture.
printfn $"The current culture is \"{thisCulture.Name}\"."
list.Sort currCmp
display list "Current culture..."
list.Sort currICCmp
display list "Current culture, ignore case..."

// Sort the list using the ordinal value of the character code points.
list.Sort ordCmp
display list "Ordinal..."
list.Sort ordICCmp
display list "Ordinal, ignore case..."

// Sort the list using the Turkish culture, which treats LATIN SMALL LETTER 
// DOTLESS I differently than LATIN SMALL LETTER I.
list.Sort turkICComp
display list "Turkish culture, ignore case..."


(*
This code example produces the following results:

The original order of the list entries...
0x49
0x69
0x131

Invariant culture...
0x69
0x49
0x131

Invariant culture, ignore case...
0x49
0x69
0x131

The current culture is "en-US".
Current culture...
0x69
0x49
0x131

Current culture, ignore case...
0x49
0x69
0x131

Ordinal...
0x49
0x69
0x131

Ordinal, ignore case...
0x69
0x49
0x131

Turkish culture, ignore case...
0x131
0x49
0x69

*)

' This code example demonstrates members of the System.StringComparer class.

Imports System.Collections
Imports System.Collections.Generic
Imports System.Globalization
Imports System.Threading

Class Sample
    
    Public Shared Sub Main() 
        ' Create a list of string.
        Dim list As New List(Of String) 
        
        ' Get the tr-TR (Turkish-Turkey) culture.
        Dim turkish As New CultureInfo("tr-TR")
        
        ' Get the culture that is associated with the current thread.
        Dim thisCulture As CultureInfo = Thread.CurrentThread.CurrentCulture
        
        ' Get the standard StringComparers.
        Dim invCmp As StringComparer = StringComparer.InvariantCulture
        Dim invICCmp As StringComparer = StringComparer.InvariantCultureIgnoreCase
        Dim currCmp As StringComparer = StringComparer.CurrentCulture
        Dim currICCmp As StringComparer = StringComparer.CurrentCultureIgnoreCase
        Dim ordCmp As StringComparer = StringComparer.Ordinal
        Dim ordICCmp As StringComparer = StringComparer.OrdinalIgnoreCase
        
        ' Create a StringComparer that uses the Turkish culture and ignores case.
        Dim turkICComp As StringComparer = StringComparer.Create(turkish, True)
        
        ' Define three strings consisting of different versions of the letter I.
        ' LATIN CAPITAL LETTER I (U+0049)
        Dim capitalLetterI As String = "I"
        
        ' LATIN SMALL LETTER I (U+0069)
        Dim smallLetterI As String = "i"
        
        ' LATIN SMALL LETTER DOTLESS I (U+0131)
        Dim smallLetterDotlessI As String = "ı"
        
        ' Add the three strings to the list.
        list.Add(capitalLetterI)
        list.Add(smallLetterI)
        list.Add(smallLetterDotlessI)
        
        ' Display the original list order.
        Display(list, "The original order of the list entries...")
        
        ' Sort the list using the invariant culture.
        list.Sort(invCmp)
        Display(list, "Invariant culture...")
        list.Sort(invICCmp)
        Display(list, "Invariant culture, ignore case...")
        
        ' Sort the list using the current culture.
        Console.WriteLine("The current culture is ""{0}"".", thisCulture.Name)
        list.Sort(currCmp)
        Display(list, "Current culture...")
        list.Sort(currICCmp)
        Display(list, "Current culture, ignore case...")
        
        ' Sort the list using the ordinal value of the character code points.
        list.Sort(ordCmp)
        Display(list, "Ordinal...")
        list.Sort(ordICCmp)
        Display(list, "Ordinal, ignore case...")
        
        ' Sort the list using the Turkish culture, which treats LATIN SMALL LETTER 
        ' DOTLESS I differently than LATIN SMALL LETTER I.
        list.Sort(turkICComp)
        Display(list, "Turkish culture, ignore case...")
    
    End Sub
    
    Public Shared Sub Display(ByVal lst As List(Of String), ByVal title As String)
        Dim c As Char
        Dim s As String
        Dim codePoint As Integer

        Console.WriteLine(title)
        For Each s In lst
            c = s(0)
            codePoint = Convert.ToInt32(c)
            Console.WriteLine("0x{0:x}", codePoint)
        Next s
        Console.WriteLine()
    End Sub
End Class

'This code example produces the following results:
'
'The original order of the list entries...
'0x49
'0x69
'0x131
'
'Invariant culture...
'0x69
'0x49
'0x131
'
'Invariant culture, ignore case...
'0x49
'0x69
'0x131
'
'The current culture is "en-US".
'Current culture...
'0x69
'0x49
'0x131
'
'Current culture, ignore case...
'0x49
'0x69
'0x131
'
'Ordinal...
'0x49
'0x69
'0x131
'
'Ordinal, ignore case...
'0x69
'0x49
'0x131
'
'Turkish culture, ignore case...
'0x131
'0x49
'0x69
'

Comentarios

Un objeto derivado de la clase StringComparer incorpora operaciones de comparación, igualdad y código hash basadas en cadenas, considerando las reglas de comparación específicas de mayúsculas/minúsculas y referencias culturales. Puede usar la StringComparer clase para crear una comparación específica del tipo para ordenar los elementos de una colección genérica. Las clases como Hashtable, Dictionary<TKey,TValue>, SortedListy SortedList<TKey,TValue> usan la StringComparer clase para fines de ordenación.

Se define que una operación de comparación representada por la clase StringComparer puede ser sensible o insensible a mayúsculas y minúsculas, y utilizar reglas de comparación basadas en palabras (sensibles a la referencia cultural) o ordinales (insensibles a la referencia cultural). Para obtener más información sobre las reglas de comparación ordinal y de palabras, vea System.Globalization.CompareOptions.

Propiedades implementadas

Es posible que se confunda sobre cómo usar las propiedades de clase StringComparer debido a una aparente contradicción. La StringComparer clase se declara abstract (MustInherit en Visual Basic), lo que significa que sus miembros solo se pueden invocar en un objeto de una clase derivada de la StringComparer clase . La contradicción es que cada propiedad de la StringComparer clase se declara static (Shared en Visual Basic), lo que significa que la propiedad se puede invocar sin crear primero una clase derivada.

Puede llamar a una propiedad StringComparer directamente porque cada propiedad devuelve realmente una instancia de una clase anónima derivada de la clase StringComparer. Por consiguiente, el tipo de cada valor de propiedad es StringComparer, que es la clase base de la clase anónima, no el tipo de la propia clase anónima. Cada propiedad de clase StringComparer devuelve un objeto StringComparer que admite reglas de comparación y manejo de mayúsculas y minúsculas predefinidas.

Consulte también

• String
• CompareOptions