CaseInsensitiveHashCodeProvider.DefaultInvariant 属性

获取 CaseInsensitiveHashCodeProvider 的一个实例,该实例与 CultureInfo.InvariantCulture 关联并且始终可用。

**命名空间:**System.Collections
**程序集:**mscorlib(在 mscorlib.dll 中)

语法

声明
Public Shared ReadOnly Property DefaultInvariant As CaseInsensitiveHashCodeProvider
用法
Dim value As CaseInsensitiveHashCodeProvider

value = CaseInsensitiveHashCodeProvider.DefaultInvariant
public static CaseInsensitiveHashCodeProvider DefaultInvariant { get; }
public:
static property CaseInsensitiveHashCodeProvider^ DefaultInvariant {
    CaseInsensitiveHashCodeProvider^ get ();
}
/** @property */
public static CaseInsensitiveHashCodeProvider get_DefaultInvariant ()
public static function get DefaultInvariant () : CaseInsensitiveHashCodeProvider

属性值

CaseInsensitiveHashCodeProvider 的实例,它与 CultureInfo.InvariantCulture 关联。

备注

比较过程使用 CultureInfo.InvariantCulture 来确定大小写规则。根据区域性的不同,哈希代码比较可能会有不同的结果。有关区域性特定比较的更多信息,请参见 System.Globalization 命名空间和 编码和本地化

示例

下面的代码示例创建一个区分大小写的哈希表和一个不区分大小写的哈希表,并演示二者行为的差别,甚至是当二者包含相同的元素时各自行为的差别。

Imports System
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 'Main 

End Class 'SamplesHashtable


'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

*/
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

*/
import System.*;
import System.Collections.*;
import System.Globalization.*;

public class SamplesHashtable
{
    public static void main(String[] args)
    {
        // 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.get_DefaultInvariant(),
            CaseInsensitiveComparer.get_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}", 
            (System.Boolean)myHT1.ContainsKey("first"));
        Console.WriteLine("first is in myHT2: {0}", 
            (System.Boolean)myHT2.ContainsKey("first"));
        Console.WriteLine("first is in myHT3: {0}", 
            (System.Boolean)myHT3.ContainsKey("first"));
        Console.WriteLine("first is in myHT4: {0}", 
            (System.Boolean)myHT4.ContainsKey("first"));
    } //main
} //SamplesHashtable

/* 
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

*/

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表,请参见系统要求

版本信息

.NET Framework

受以下版本支持:2.0、1.1

.NET Compact Framework

受以下版本支持:2.0、1.0

请参见

参考

CaseInsensitiveHashCodeProvider 类
CaseInsensitiveHashCodeProvider 成员
System.Collections 命名空间
CultureInfo.InvariantCulture

其他资源

在集合中执行不区分区域性的字符串操作