Comparer 类

定义

命名空间:

System.Collections

程序集:

System.Runtime.dll

Source:

Comparer.cs

比较两个对象是否相等，其中字符串比较是区分大小写的。

public ref class Comparer sealed : System::Collections::IComparer, System::Runtime::Serialization::ISerializable

public sealed class Comparer : System.Collections.IComparer, System.Runtime.Serialization.ISerializable

type Comparer = class
    interface IComparer
    interface ISerializable

Public NotInheritable Class Comparer
Implements IComparer, ISerializable

继承

Object

Comparer

实现

IComparer ISerializable

示例

下面的代码示例演示如何 Compare 根据与 Comparer关联的区域性返回不同的值。

using namespace System;
using namespace System::Collections;
using namespace System::Globalization;
int main()
{
   
   // Creates the strings to compare.
   String^ str1 = "llegar";
   String^ str2 = "lugar";
   Console::WriteLine( "Comparing \"{0}\" and \"{1}\" ...", str1, str2 );
   
   // Uses the DefaultInvariant Comparer.
   Console::WriteLine( "   Invariant Comparer: {0}", Comparer::DefaultInvariant->Compare( str1, str2 ) );
   
   // Uses the Comparer based on the culture "es-ES" (Spanish - Spain, international sort).
   Comparer^ myCompIntl = gcnew Comparer( gcnew CultureInfo(  "es-ES",false ) );
   Console::WriteLine( "   International Sort: {0}", myCompIntl->Compare( str1, str2 ) );
   
   // Uses the Comparer based on the culture identifier 0x040A (Spanish - Spain, traditional sort).
   Comparer^ myCompTrad = gcnew Comparer( gcnew CultureInfo( 0x040A,false ) );
   Console::WriteLine( "   Traditional Sort  : {0}", myCompTrad->Compare( str1, str2 ) );
}

/*
This code produces the following output.

Comparing "llegar" and "lugar" ...
   Invariant Comparer: -1
   International Sort: -1
   Traditional Sort  : 1

*/

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

public class SamplesComparer  {

   public static void Main()  {

      // Creates the strings to compare.
      String str1 = "llegar";
      String str2 = "lugar";
      Console.WriteLine( "Comparing \"{0}\" and \"{1}\" ...", str1, str2 );

      // Uses the DefaultInvariant Comparer.
      Console.WriteLine( "   Invariant Comparer: {0}", Comparer.DefaultInvariant.Compare( str1, str2 ) );

      // Uses the Comparer based on the culture "es-ES" (Spanish - Spain, international sort).
      Comparer myCompIntl = new Comparer( new CultureInfo( "es-ES", false ) );
      Console.WriteLine( "   International Sort: {0}", myCompIntl.Compare( str1, str2 ) );

      // Uses the Comparer based on the culture identifier 0x040A (Spanish - Spain, traditional sort).
      Comparer myCompTrad = new Comparer( new CultureInfo( 0x040A, false ) );
      Console.WriteLine( "   Traditional Sort  : {0}", myCompTrad.Compare( str1, str2 ) );
   }
}

/*
This code produces the following output.

Comparing "llegar" and "lugar" ...
   Invariant Comparer: -1
   International Sort: -1
   Traditional Sort  : 1

*/

Imports System.Collections
Imports System.Globalization

Public Class SamplesComparer

   Public Shared Sub Main()

      ' Creates the strings to compare.
      Dim str1 As [String] = "llegar"
      Dim str2 As [String] = "lugar"
      Console.WriteLine("Comparing ""{0}"" and ""{1}"" ...", str1, str2)

      ' Uses the DefaultInvariant Comparer.
      Console.WriteLine("   Invariant Comparer: {0}", Comparer.DefaultInvariant.Compare(str1, str2))

      ' Uses the Comparer based on the culture "es-ES" (Spanish - Spain, international sort).
      Dim myCompIntl As New Comparer(New CultureInfo("es-ES", False))
      Console.WriteLine("   International Sort: {0}", myCompIntl.Compare(str1, str2))

      ' Uses the Comparer based on the culture identifier 0x040A (Spanish - Spain, traditional sort).
      Dim myCompTrad As New Comparer(New CultureInfo(&H40A, False))
      Console.WriteLine("   Traditional Sort  : {0}", myCompTrad.Compare(str1, str2))

   End Sub

End Class


'This code produces the following output.
'
'Comparing "llegar" and "lugar" ...
'   Invariant Comparer: -1
'   International Sort: -1
'   Traditional Sort  : 1

注解

此类是 接口的默认实现 IComparer 。 类 CaseInsensitiveComparer 是接口的实现， IComparer 该接口执行不区分大小写的字符串比较。 System.Collections.Generic.Comparer<T> 是此类的泛型等效项。

除非另行指定，否则比较过程使用 Thread.CurrentCulture 当前线程的 。 字符串比较可能具有不同的结果，具体取决于区域性。 有关特定于区域性的比较的详细信息，请参阅 System.Globalization 命名空间和 全球化和本地化。

构造函数

Comparer(CultureInfo)

使用指定的 Comparer 初始化 CultureInfo 类的新实例。

字段

Default	表示 Comparer 的实例，它与当前线程的 CurrentCulture 关联。 此字段为只读。
DefaultInvariant	表示 Comparer 的实例，它与 InvariantCulture 关联。 此字段为只读。

方法

Compare(Object, Object)	对同一类型的两个对象执行区分大小写的比较，并返回一个值，指示其中一个对象小于、等于还是大于另一个对象。
Equals(Object)	确定指定对象是否等于当前对象。 (继承自 Object)
GetHashCode()	作为默认哈希函数。 (继承自 Object)
GetObjectData(SerializationInfo, StreamingContext)	已过时. 用序列化所需的数据填充 SerializationInfo 对象。
GetType()	获取当前实例的 Type。 (继承自 Object)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
ToString()	返回表示当前对象的字符串。 (继承自 Object)

另请参阅

• IComparer
• IComparable
• CaseInsensitiveComparer
• Comparer<T>
• CompareInfo
• CurrentCulture
• CultureInfo