StringComparer 类

定义

表示一种字符串比较操作,该操作使用特定的大小写以及基于区域性的比较规则或序号比较规则。

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)
继承
StringComparer
属性
实现

示例

以下示例演示类的属性和 Create 方法 StringComparer 。 该示例说明了不同 StringComparer 对象如何对拉丁文字母 I 的三个版本进行排序。

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

using namespace System;
using namespace System::Collections;
using namespace System::Collections::Generic;
using namespace System::Globalization;
using namespace System::Threading;

void Display(List<String^>^ stringList, String^ title)
{
    Char firstChar;
    int codePoint;
    Console::WriteLine(title);
    for each (String^ s in stringList)
    {
        firstChar = s[0];
        codePoint = Convert::ToInt32(firstChar);
        Console::WriteLine("0x{0:x}", codePoint);
    }
    Console::WriteLine();
}

int main()
{
    // Create a list of string.
    List<String^>^ stringList = gcnew List<String^>();

    // Get the tr-TR (Turkish-Turkey) culture.
    CultureInfo^ turkishCulture = gcnew CultureInfo("tr-TR");

    // Get the culture that is associated with the current thread.
    CultureInfo^ currentCulture = Thread::CurrentThread->CurrentCulture;

    // Get the standard StringComparers.
    StringComparer^ invariant = StringComparer::InvariantCulture;
    StringComparer^ invariantIgnoreCase =
        StringComparer::InvariantCultureIgnoreCase;
    StringComparer^ current = StringComparer::CurrentCulture;
    StringComparer^ currentIgnoreCase =
        StringComparer::CurrentCultureIgnoreCase;
    StringComparer^ ordinal = StringComparer::Ordinal;
    StringComparer^ ordinalIgnoreCase = StringComparer::OrdinalIgnoreCase;

    // Create a StringComparer that uses the Turkish culture and ignores
    // case.
    StringComparer^ turkishIgnoreCase =
        StringComparer::Create(turkishCulture, 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 = L"\u0131";

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

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

    // Sort the list using the invariant culture.
    stringList->Sort(invariant);
    Display(stringList, "Invariant culture...");
    stringList->Sort(invariantIgnoreCase);
    Display(stringList, "Invariant culture, ignore case...");

    // Sort the list using the current culture.
    Console::WriteLine("The current culture is \"{0}\".",
        currentCulture->Name);
    stringList->Sort(current);
    Display(stringList, "Current culture...");
    stringList->Sort(currentIgnoreCase);
    Display(stringList, "Current culture, ignore case...");

    // Sort the list using the ordinal value of the character code points.
    stringList->Sort(ordinal);
    Display(stringList, "Ordinal...");
    stringList->Sort(ordinalIgnoreCase);
    Display(stringList, "Ordinal, ignore case...");

    // Sort the list using the Turkish culture, which treats LATIN SMALL
    // LETTER DOTLESS I differently than LATIN SMALL LETTER I.
    stringList->Sort(turkishIgnoreCase);
    Display(stringList, "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 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
'

注解

StringComparer 类派生的对象体现了基于字符串的比较、相等性和哈希代码操作,这些操作同时考虑事例和区域性特定的比较规则。 可以使用 StringComparer 该类创建特定于类型的比较来对泛型集合中的元素进行排序。 类(例如HashtableDictionary<TKey,TValue>SortedList并使用SortedList<TKey,TValue>StringComparer类进行排序。

类表示 StringComparer 的比较操作定义为区分大小写或不区分大小写,并使用区分区域性的单词 (区分区域性) 或序号 (不区分区域性) 比较规则。 有关单词和序号比较规则的详细信息,请参阅 System.Globalization.CompareOptions

备注

可以下载排序权重表,这是一组文本文件,其中包含有关 Windows 操作系统排序和比较操作中所使用的字符权重的信息,也可以下载默认 Unicode 排序元素表,这是适用于 Linux 和 macOS 的最新版排序权重表。 Linux 和 macOS 上的特定排序权重表版本取决于系统上安装的 International Components for Unicode 库的版本。 有关 ICU 版本及它们所实现的 Unicode 版本的信息,请参阅下载 ICU

已实现的属性

由于看似矛盾,你可能对如何使用 StringComparer 类属性感到困惑。 类StringComparerabstractVisual Basic) 中声明 (MustInherit,这意味着只能在派生自StringComparer该类的类的对象上调用其成员。 矛盾在于,类static的每个属性StringComparer在Visual Basic) 中声明 (Shared,这意味着可以在不首先创建派生类的情况下调用该属性。

可以直接调用属性, StringComparer 因为每个属性实际上返回派生自 StringComparer 该类的匿名类的实例。 因此,每个属性值的类型是 StringComparer匿名类的基类,而不是匿名类本身的类型。 每个 StringComparer 类属性返回一个 StringComparer 支持预定义事例和比较规则的对象。

构造函数

StringComparer()

初始化 StringComparer 类的新实例。

属性

CurrentCulture

获取一个 StringComparer 对象,该对象使用当前区域性的单词比较规则执行区分大小写的字符串比较。

CurrentCultureIgnoreCase

获取一个 StringComparer 对象,该对象使用当前区域性的单词比较规则执行不区分大小写的字符串比较。

InvariantCulture

获取一个 StringComparer 对象,该对象使用固定区域性的单词比较规则执行区分大小写的字符串比较。

InvariantCultureIgnoreCase

获取一个 StringComparer 对象,该对象使用固定区域性的单词比较规则执行不区分大小写的字符串比较。

Ordinal

获取 StringComparer 对象,该对象执行区分大小写的序号字符串比较。

OrdinalIgnoreCase

获取 StringComparer 对象,该对象执行不区分大小写的序号字符串比较。

方法

Compare(Object, Object)

当在派生类中重写时,将比较两个对象并返回其相对排序顺序的指示。

Compare(String, String)

当在派生类中重写时,将比较两个字符串并返回其相对排序顺序的指示。

Create(CultureInfo, Boolean)

创建 StringComparer 对象,该对象根据指定区域性的规则对字符串进行比较。

Create(CultureInfo, CompareOptions)

创建一个 StringComparer 对象,该对象根据指定的区域性和字符串选项的规则对字符串进行比较。

Equals(Object)

确定指定对象是否等于当前对象。

(继承自 Object)
Equals(Object, Object)

当在派生类中重写时,指示两个对象是否相等。

Equals(String, String)

当在派生类中重写时,指示两个字符串是否相等。

FromComparison(StringComparison)

将指定的 StringComparison 实例转换为 StringComparer 实例。

GetHashCode()

作为默认哈希函数。

(继承自 Object)
GetHashCode(Object)

当在派生类中重写时,将获取指定对象的哈希代码。

GetHashCode(String)

当在派生类中重写时,将获取指定字符串的哈希代码。

GetType()

获取当前实例的 Type

(继承自 Object)
IsWellKnownCultureAwareComparer(IEqualityComparer<String>, CompareInfo, CompareOptions)

确定指定 IEqualityComparer<T> 是否为已知区域性感知字符串比较器。

IsWellKnownOrdinalComparer(IEqualityComparer<String>, Boolean)

确定指定 IEqualityComparer<T> 是否为已知的序号字符串比较器。

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)

显式接口实现

IComparer.Compare(Object, Object)

比较两个对象并返回一个值,该值指示一个对象小于、等于还是大于另一个对象。

IEqualityComparer.Equals(Object, Object)

确定指定的对象是否相等。

IEqualityComparer.GetHashCode(Object)

返回指定对象的哈希代码。

适用于

另请参阅