CaseInsensitiveComparer 類別

  • 參考

定義

命名空間:
System.Collections
組件:
mscorlib.dll, System.Collections.NonGeneric.dll
組件:
System.Collections.NonGeneric.dll
組件:
mscorlib.dll
組件:
netstandard.dll

比較兩個物件是否相等，忽略字串的大小寫。

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
繼承
Object
CaseInsensitiveComparer
屬性
SerializableAttribute ComVisibleAttribute
實作
IComparer

範例

下列程式碼範例會建立區分大小寫的雜湊表和不區分大小寫的雜湊表，並示範其行為的差異，即使兩者都包含相同的元素也一樣。

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

備註

CaseInsensitiveComparer實 IComparer 作支援字串不區分大小寫比較的介面，就像實 IHashCodeProvider 作支援字串不區分大小寫比較的介面一樣 CaseInsensitiveHashCodeProvider 。

重要

不建議您將 類別用於 CaseInsensitiveComparer 新的開發。 相反地，建議您使用 System.StringComparer 、 StringComparer.InvariantCultureIgnoreCase 或 StringComparer.OrdinalIgnoreCase 屬性所 StringComparer.CurrentCultureIgnoreCase 傳回的物件。

類別 Comparer 是 介面的預設實作 IComparer ，並執行區分大小寫的字串比較。

若要覆寫 Object.GetHashCode 方法 (或 IHashCodeProvider 介面) ，以及 Object.Equals 方法 (或 IComparer 介面) ，則需要用來做為索引鍵 Hashtable 的物件。 這兩種方法或介面的實作必須以相同方式處理區分大小寫;否則， Hashtable 的行為可能會不正確。 例如，建立 Hashtable 時，您必須將此類別與 類別或任何不區分大小寫的實作 IHashCodeProvider 搭配 CaseInsensitiveHashCodeProvider 使用。

根據文化特性，字串比較可能會有不同的結果。 如需特定文化特性比較的詳細資訊，請參閱 System.Globalization 命名空間和 全球化和當地語系化。

建構函式

CaseInsensitiveComparer()

使用目前執行緒的 CaseInsensitiveComparer，初始化 CurrentCulture 類別的新執行個體。
CaseInsensitiveComparer(CultureInfo)

使用指定的 CaseInsensitiveComparer，初始化 CultureInfo 類別的新執行個體。

屬性

Default

取得 CaseInsensitiveComparer 的執行個體，它與目前執行緒的 CurrentCulture 相關聯，而且永遠可以使用。
DefaultInvariant

取得 CaseInsensitiveComparer 的執行個體，它與 InvariantCulture 相關聯，而且永遠可以使用。

方法

Compare(Object, Object)

執行兩個相同型別物件的區分大小寫比較，並傳回表示是否某個物件小於、等於或大於另外一方的值。
Equals(Object)

判斷指定的物件是否等於目前的物件。

(繼承來源 Object)
GetHashCode()

做為預設雜湊函式。

(繼承來源 Object)
GetType()

取得目前執行個體的 Type。

(繼承來源 Object)
MemberwiseClone()

建立目前 Object 的淺層複製。

(繼承來源 Object)
ToString()

傳回代表目前物件的字串。

(繼承來源 Object)

適用於

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