CaseInsensitiveComparer Класс

public ref class CaseInsensitiveComparer : System::Collections::IComparer

public class CaseInsensitiveComparer : System.Collections.IComparer

[System.Serializable]
public class CaseInsensitiveComparer : System.Collections.IComparer

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public class CaseInsensitiveComparer : System.Collections.IComparer

type CaseInsensitiveComparer = class
    interface IComparer

[<System.Serializable>]
type CaseInsensitiveComparer = class
    interface IComparer

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

Public Class CaseInsensitiveComparer
Implements IComparer

Наследование

Object

CaseInsensitiveComparer

Атрибуты

SerializableAttribute ComVisibleAttribute

Реализации

IComparer

В следующем примере кода создаются хэш-таблица с учетом регистра и хэш-таблица без учета регистра и демонстрируется разница в их поведении, даже если они содержат одни и те же элементы.

using namespace System;
using namespace System::Collections;
using namespace System::Globalization;
int main()
{
   
   // Create a Hashtable using the default hash code provider and the default comparer.
   Hashtable^ myHT1 = gcnew Hashtable;
   myHT1->Add( "FIRST", "Hello" );
   myHT1->Add( "SECOND", "World" );
   myHT1->Add( "THIRD", "!" );
   
   // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
   // based on the culture of the current thread.
   Hashtable^ myHT2 = gcnew Hashtable( gcnew CaseInsensitiveHashCodeProvider,gcnew CaseInsensitiveComparer );
   myHT2->Add( "FIRST", "Hello" );
   myHT2->Add( "SECOND", "World" );
   myHT2->Add( "THIRD", "!" );
   
   // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
   // based on the InvariantCulture.
   Hashtable^ myHT3 = gcnew Hashtable( CaseInsensitiveHashCodeProvider::DefaultInvariant,CaseInsensitiveComparer::DefaultInvariant );
   myHT3->Add( "FIRST", "Hello" );
   myHT3->Add( "SECOND", "World" );
   myHT3->Add( "THIRD", "!" );
   
   // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
   // based on the Turkish culture (tr-TR), where "I" is not the uppercase version of "i".
   CultureInfo^ myCul = gcnew CultureInfo( "tr-TR" );
   Hashtable^ myHT4 = gcnew Hashtable( gcnew CaseInsensitiveHashCodeProvider( myCul ),gcnew CaseInsensitiveComparer( myCul ) );
   myHT4->Add( "FIRST", "Hello" );
   myHT4->Add( "SECOND", "World" );
   myHT4->Add( "THIRD", "!" );
   
   // Search for a key in each hashtable.
   Console::WriteLine( "first is in myHT1: {0}", myHT1->ContainsKey( "first" ) );
   Console::WriteLine( "first is in myHT2: {0}", myHT2->ContainsKey( "first" ) );
   Console::WriteLine( "first is in myHT3: {0}", myHT3->ContainsKey( "first" ) );
   Console::WriteLine( "first is in myHT4: {0}", myHT4->ContainsKey( "first" ) );
}

/* 
This code produces the following output.  Results vary depending on the system's culture settings.

first is in myHT1: False
first is in myHT2: True
first is in myHT3: True
first is in myHT4: False

*/

using System;
using System.Collections;
using System.Globalization;

public class SamplesHashtable  {

   public static void Main()  {

      // Create a Hashtable using the default hash code provider and the default comparer.
      Hashtable myHT1 = new Hashtable();
      myHT1.Add("FIRST", "Hello");
      myHT1.Add("SECOND", "World");
      myHT1.Add("THIRD", "!");

      // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      // based on the culture of the current thread.
      Hashtable myHT2 = new Hashtable( new CaseInsensitiveHashCodeProvider(), new CaseInsensitiveComparer() );
      myHT2.Add("FIRST", "Hello");
      myHT2.Add("SECOND", "World");
      myHT2.Add("THIRD", "!");

      // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      // based on the InvariantCulture.
      Hashtable myHT3 = new Hashtable( CaseInsensitiveHashCodeProvider.DefaultInvariant, CaseInsensitiveComparer.DefaultInvariant );
      myHT3.Add("FIRST", "Hello");
      myHT3.Add("SECOND", "World");
      myHT3.Add("THIRD", "!");

      // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      // based on the Turkish culture (tr-TR), where "I" is not the uppercase version of "i".
      CultureInfo myCul = new CultureInfo( "tr-TR" );
      Hashtable myHT4 = new Hashtable( new CaseInsensitiveHashCodeProvider( myCul ), new CaseInsensitiveComparer( myCul ) );
      myHT4.Add("FIRST", "Hello");
      myHT4.Add("SECOND", "World");
      myHT4.Add("THIRD", "!");

      // Search for a key in each hashtable.
      Console.WriteLine( "first is in myHT1: {0}", myHT1.ContainsKey( "first" ) );
      Console.WriteLine( "first is in myHT2: {0}", myHT2.ContainsKey( "first" ) );
      Console.WriteLine( "first is in myHT3: {0}", myHT3.ContainsKey( "first" ) );
      Console.WriteLine( "first is in myHT4: {0}", myHT4.ContainsKey( "first" ) );
   }
}


/*
This code produces the following output.  Results vary depending on the system's culture settings.

first is in myHT1: False
first is in myHT2: True
first is in myHT3: True
first is in myHT4: False

*/

Imports System.Collections
Imports System.Globalization

Public Class SamplesHashtable

   Public Shared Sub Main()

      ' Create a Hashtable using the default hash code provider and the default comparer.
      Dim myHT1 As New Hashtable()
      myHT1.Add("FIRST", "Hello")
      myHT1.Add("SECOND", "World")
      myHT1.Add("THIRD", "!")

      ' Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      ' based on the culture of the current thread.
      Dim myHT2 As New Hashtable(New CaseInsensitiveHashCodeProvider(), New CaseInsensitiveComparer())
      myHT2.Add("FIRST", "Hello")
      myHT2.Add("SECOND", "World")
      myHT2.Add("THIRD", "!")

      ' Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      ' based on the InvariantCulture.
      Dim myHT3 As New Hashtable(CaseInsensitiveHashCodeProvider.DefaultInvariant, CaseInsensitiveComparer.DefaultInvariant)
      myHT3.Add("FIRST", "Hello")
      myHT3.Add("SECOND", "World")
      myHT3.Add("THIRD", "!")

      ' Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      ' based on the Turkish culture (tr-TR), where "I" is not the uppercase version of "i".
      Dim myCul As New CultureInfo("tr-TR")
      Dim myHT4 As New Hashtable(New CaseInsensitiveHashCodeProvider(myCul), New CaseInsensitiveComparer(myCul))
      myHT4.Add("FIRST", "Hello")
      myHT4.Add("SECOND", "World")
      myHT4.Add("THIRD", "!")

      ' Search for a key in each hashtable.
      Console.WriteLine("first is in myHT1: {0}", myHT1.ContainsKey("first"))
      Console.WriteLine("first is in myHT2: {0}", myHT2.ContainsKey("first"))
      Console.WriteLine("first is in myHT3: {0}", myHT3.ContainsKey("first"))
      Console.WriteLine("first is in myHT4: {0}", myHT4.ContainsKey("first"))

   End Sub

End Class


'This code produces the following output.  Results vary depending on the system's culture settings.
'
'first is in myHT1: False
'first is in myHT2: True
'first is in myHT3: True
'first is in myHT4: False

CaseInsensitiveComparer IComparer реализует интерфейс, поддерживающий сравнения строк без учета регистра, так же как CaseInsensitiveHashCodeProvider реализует IHashCodeProvider интерфейс, поддерживающий сравнение строк без учета регистра.

Класс Comparer является реализацией IComparer интерфейса по умолчанию и выполняет сравнение строк с учетом регистра.

Объекты, используемые в качестве ключей, Hashtable необходимы для переопределения Object.GetHashCode метода (или IHashCodeProvider интерфейса) и Object.Equals метода (или IComparer интерфейса). Реализация обоих методов или интерфейсов должна одинаково обрабатывать чувствительность к регистру; В Hashtable противном случае объект может вести себя неправильно. Например, при создании Hashtableнеобходимо использовать этот класс с классом CaseInsensitiveHashCodeProvider или любой реализацией без учета IHashCodeProvider регистра.

Сравнение строк может иметь разные результаты в зависимости от языка и региональных параметров. Дополнительные сведения о сравнениях с учетом языка и региональных параметров см. в System.Globalization разделе Пространство имен и Глобализация и локализация.

• IComparer
• IComparable
• Comparer
• CompareInfo
• CurrentCulture
• CultureInfo
• CaseInsensitiveHashCodeProvider
• Выполнение строковых операций без учета языка и региональных параметров в коллекциях