String.Compare 方法

定义

比较两个指定的 String 对象,并返回一个指示二者在排序顺序中的相对位置的整数。

重载

Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions)

对两个指定 String 对象的子字符串进行比较,使用指定的比较选项和区域性特定的信息来影响比较,并返回一个整数,该整数指示这两个子字符串在排序顺序中的关系。

Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)

比较两个指定的 String 对象(其中忽略或考虑其大小写,并使用区域性特定的信息干预比较),并返回一个整数,指示二者在排序顺序中的相对位置。

Compare(String, Int32, String, Int32, Int32, StringComparison)

使用指定的规则比较两个指定的 String 对象的子字符串,并返回一个整数,指示二者在排序顺序中的相对位置。

Compare(String, Int32, String, Int32, Int32, Boolean)

比较两个指定的 String 对象的子字符串(忽略或考虑其大小写),并返回一个整数,指示二者在排序顺序中的相对位置。

Compare(String, Int32, String, Int32, Int32)

比较两个指定的 String 对象的子字符串,并返回一个指示二者在排序顺序中的相对位置的整数。

Compare(String, String)

比较两个指定的 String 对象,并返回一个指示二者在排序顺序中的相对位置的整数。

Compare(String, String, Boolean, CultureInfo)

比较两个指定的 String 对象(其中忽略或考虑其大小写,并使用区域性特定的信息干预比较),并返回一个整数,指示二者在排序顺序中的相对位置。

Compare(String, String, StringComparison)

使用指定的规则比较两个指定的 String 对象,并返回一个整数,指示二者在排序顺序中的相对位置。

Compare(String, String, Boolean)

比较两个指定的 String 对象(其中忽略或考虑其大小写),并返回一个整数,指示二者在排序顺序中的相对位置。

Compare(String, String, CultureInfo, CompareOptions)

对两个指定的 String 对象进行比较,使用指定的比较选项和区域性特定的信息来影响比较,并返回一个整数,该整数指示这两个字符串在排序顺序中的关系。

注解

Compare 方法的所有重载返回一个 32 位有符号整数,指示两个比较数之间的词法关系。

“值” 条件
小于零 在排序顺序中,第一个子字符串在第二个子字符串之前。
子字符串在排序顺序中出现的位置相同或 length 为零。
大于零 第一个子字符串在排序顺序中后跟第二个子字符串。

警告

应尽可能调用 Compare 包含参数的方法的重载 StringComparison 。 有关详细信息,请参阅有关使用字符串的最佳实践

Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions)

对两个指定 String 对象的子字符串进行比较,使用指定的比较选项和区域性特定的信息来影响比较,并返回一个整数,该整数指示这两个子字符串在排序顺序中的关系。

public:
 static int Compare(System::String ^ strA, int indexA, System::String ^ strB, int indexB, int length, System::Globalization::CultureInfo ^ culture, System::Globalization::CompareOptions options);
public static int Compare (string? strA, int indexA, string? strB, int indexB, int length, System.Globalization.CultureInfo? culture, System.Globalization.CompareOptions options);
public static int Compare (string strA, int indexA, string strB, int indexB, int length, System.Globalization.CultureInfo culture, System.Globalization.CompareOptions options);
static member Compare : string * int * string * int * int * System.Globalization.CultureInfo * System.Globalization.CompareOptions -> int
Public Shared Function Compare (strA As String, indexA As Integer, strB As String, indexB As Integer, length As Integer, culture As CultureInfo, options As CompareOptions) As Integer

参数

strA
String

要在比较中使用的第一个字符串。

indexA
Int32

strA 中子字符串开始的位置。

strB
String

要在比较中使用的第二个字符串。

indexB
Int32

strB 中子字符串开始的位置。

length
Int32

要比较的子字符串中字符的最大数量。

culture
CultureInfo

一个对象,提供区域性特定的比较信息。 如果 culturenull,则使用当前区域性。

options
CompareOptions

要在执行比较时使用的选项(如忽略大小写或符号)。

返回

Int32

一个整数,该整数用于指示两个子字符串之间的词法关系,如下表所示。

“值” 条件
小于零 strA 中的子字符串在排序顺序中位于 strB 中的子字符串之前。
子字符串在排序顺序中出现的位置相同或 length 为零。
大于零 strA 中的子字符串在排序顺序中位于 strB 中的子字符串之后。

例外

options 不是 CompareOptions 值。

indexA 大于 strA.Length

  • 或 -

indexB 大于 strB.Length

  • 或 -

indexAindexBlength 为负数。

  • 或 -

strAstrBnull,并且 length 大于零。

示例

下面的示例使用 Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions) 方法比较两个人的名字。 然后,它按字母顺序列出它们。

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      string name1 = "Jack Smith";
      string name2 = "John Doe";
      
      // Get position of character after the space character.
      int index1 = name1.IndexOf(" ");
      index1 = index1 < 0 ? 0 : ++index1;
      
      int index2 = name2.IndexOf(" ");
      index2 = index2 < 0 ? 0 : ++index2;
      
      int length = Math.Max(name1.Length, name2.Length);
      
      Console.WriteLine("Sorted alphabetically by last name:");
      if (String.Compare(name1, index1, name2, index2, length, 
                         new CultureInfo("en-US"), CompareOptions.IgnoreCase) < 0)
         Console.WriteLine("{0}\n{1}", name1, name2); 
      else
         Console.WriteLine("{0}\n{1}", name2, name1); 
   }
}
// The example displays the following output:
//       Sorted alphabetically by last name:
//       John Doe
//       Jack Smith
Imports System.Globalization

Module Example
   Public Sub Main()
      Dim name1 As String = "Jack Smith"
      Dim name2 = "John Doe"
      
      ' Get position of space character.
      Dim index1 As Integer = name1.IndexOf(" ")
      index1 = CInt(IIf(index1 < 0, 0, index1 - 1))
      
      Dim index2 As Integer = name2.IndexOf(" ")
      index1 = CInt(IIf(index1 < 0, 0, index1 - 1))
      
      Dim length As Integer = Math.Max(name1.Length, name2.Length)
      
      Console.WriteLIne("Sorted alphabetically by last name:")
      If String.Compare(name1, index1, name2, index2, length, _
                        New CultureInfo("en-US"), CompareOptions.IgnoreCase) < 0 Then
         Console.WriteLine("{0}{1}{2}", name1, vbCrLf, name2)
      Else
         Console.WriteLine("{0}{1}{2}", name2, vbCrLf, name1)
      End If
   End Sub
End Module
' The example displays the following output;
'       Sorted alphabetically by last name:
'       John Doe
'       Jack Smith

注解

要比较的子字符串从 位置 strA 开始, indexA 在 位置 strB 开始 indexB 。 第一个子字符串的长度是减去 strA 的长度 indexA 。 第二个子字符串的长度是减去 strB 的长度 indexB

要比较的字符数是两个子字符串 和 的长度中较小 length 者。 、 indexA indexBlength 参数必须无要求。

比较使用 culture 参数获取区域性特定信息,例如大小写规则和单个字符的字母顺序。 例如,特定区域性可以指定将字符的某些组合视为单个字符、以特定方式比较大写字符和小写字符,或指定字符的排序顺序取决于它之前或之后的字符。

注意

Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions)方法主要用于排序或按字母顺序排序操作。 当方法调用的主要用途是确定两个子字符串是否等效时,不应使用 (也就是说,当方法调用的目的是测试返回值零值时) 。 若要确定两个字符串是否等效,请调用 Equals 方法。

和 的一个或 strAstrB 个可以是 null 。 根据定义,任何字符串(包括 String.Empty )都比较大于 null 引用,两个 null 引用相互比较相等。

可通过 参数进一步指定比较 options ,该参数由 枚举的一个或多个 System.Globalization.CompareOptions 成员组成。 但是,由于此方法的目的是进行区分区域性的字符串比较,因此 和 CompareOptions.Ordinal CompareOptions.OrdinalIgnoreCase 值不起作用。

当发现不相等或已比较两个子字符串时,比较将终止。 但是,如果两个字符串的比较结果等于一个字符串的末尾,而另一个字符串有剩余字符,则剩余字符的字符串将被视为更大的字符串。 返回值是上次执行的比较的结果。

调用方说明

字符集包括可忽略字符。 Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions)方法执行语言或区分区域性的比较时不考虑这些字符。 若要识别比较中的可忽略字符,请为 Ordinal 参数提供 或 OrdinalIgnoreCase options 值。

另请参阅

适用于

Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)

比较两个指定的 String 对象(其中忽略或考虑其大小写,并使用区域性特定的信息干预比较),并返回一个整数,指示二者在排序顺序中的相对位置。

public:
 static int Compare(System::String ^ strA, int indexA, System::String ^ strB, int indexB, int length, bool ignoreCase, System::Globalization::CultureInfo ^ culture);
public static int Compare (string? strA, int indexA, string? strB, int indexB, int length, bool ignoreCase, System.Globalization.CultureInfo? culture);
public static int Compare (string strA, int indexA, string strB, int indexB, int length, bool ignoreCase, System.Globalization.CultureInfo culture);
static member Compare : string * int * string * int * int * bool * System.Globalization.CultureInfo -> int
Public Shared Function Compare (strA As String, indexA As Integer, strB As String, indexB As Integer, length As Integer, ignoreCase As Boolean, culture As CultureInfo) As Integer

参数

strA
String

要在比较中使用的第一个字符串。

indexA
Int32

strA 中子字符串的位置。

strB
String

要在比较中使用的第二个字符串。

indexB
Int32

strB 中子字符串的位置。

length
Int32

要比较的子字符串中字符的最大数量。

ignoreCase
Boolean

若要在比较过程中忽略大小写,则为 true;否则为 false

culture
CultureInfo

一个对象,提供区域性特定的比较信息。 如果 culturenull,则使用当前区域性。

返回

Int32

一个整数,指示两个比较字之间的词法关系。

“值” 条件
小于零 strA 中的子字符串在排序顺序中位于 strB 中的子字符串之前。
子字符串在排序顺序中出现的位置相同或 length 为零。
大于零 strA 中的子字符串在排序顺序中位于 strB 中的子字符串之后。

例外

indexA 大于 strA.Length

  • 或 -

indexB 大于 strB.Length

  • 或 -

indexAindexBlength 为负数。

  • 或 -

strAstrBnull,并且 length 大于零。

示例

下面的示例比较两个使用不同区域性的子字符串,并忽略子字符串的大小写。 区域性的选择会影响字母"I"的比较。

// Sample for String::Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)
using namespace System;
using namespace System::Globalization;
int main()
{
   
   //                0123456
   String^ str1 = "MACHINE";
   String^ str2 = "machine";
   String^ str;
   int result;
   Console::WriteLine();
   Console::WriteLine( "str1 = '{0}', str2 = '{1}'", str1, str2 );
   Console::WriteLine( "Ignore case, Turkish culture:" );
   result = String::Compare( str1, 4, str2, 4, 2, true, gcnew CultureInfo( "tr-TR" ) );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in '{1}' is ", str1->Substring( 4, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in '{1}'.", str2->Substring( 4, 2 ), str2 );
   Console::WriteLine();
   Console::WriteLine( "Ignore case, invariant culture:" );
   result = String::Compare( str1, 4, str2, 4, 2, true, CultureInfo::InvariantCulture );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in '{1}' is ", str1->Substring( 4, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in '{1}'.", str2->Substring( 4, 2 ), str2 );
}

/*
This example produces the following results:

str1 = 'MACHINE', str2 = 'machine'
Ignore case, Turkish culture:
Substring 'IN' in 'MACHINE' is less than substring 'in' in 'machine'.

Ignore case, invariant culture:
Substring 'IN' in 'MACHINE' is equal to substring 'in' in 'machine'.
*/
// Sample for String.Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)
using System;
using System.Globalization;

class Sample5
{
    public static void Main()
    {
        //                 0123456
        String str1 = "MACHINE";
        String str2 = "machine";
        String str;
        int result;

        Console.WriteLine();
        Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2);
        Console.WriteLine("Ignore case, Turkish culture:");
        result = String.Compare(str1, 4, str2, 4, 2, true, new CultureInfo("tr-TR"));
        str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
        Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(4, 2), str1);
        Console.Write("{0} ", str);
        Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(4, 2), str2);

        Console.WriteLine();
        Console.WriteLine("Ignore case, invariant culture:");
        result = String.Compare(str1, 4, str2, 4, 2, true, CultureInfo.InvariantCulture);
        str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
        Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(4, 2), str1);
        Console.Write("{0} ", str);
        Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(4, 2), str2);
    }
}
/*
This example produces the following results:

str1 = 'MACHINE', str2 = 'machine'
Ignore case, Turkish culture:
Substring 'IN' in 'MACHINE' is less than substring 'in' in 'machine'.

Ignore case, invariant culture:
Substring 'IN' in 'MACHINE' is equal to substring 'in' in 'machine'.
*/
' Sample for String.Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)
Imports System.Globalization

Class Sample
   
   Public Shared Sub Main()
      '                       0123456
      Dim str1 As [String] = "MACHINE"
      Dim str2 As [String] = "machine"
      Dim str As [String]
      Dim result As Integer
      
      Console.WriteLine()
      Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2)
      Console.WriteLine("Ignore case, Turkish culture:")
      result = [String].Compare(str1, 4, str2, 4, 2, True, New CultureInfo("tr-TR"))
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(4, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(4, 2), str2)
      
      Console.WriteLine()
      Console.WriteLine("Ignore case, invariant culture:")
      result = [String].Compare(str1, 4, str2, 4, 2, True, CultureInfo.InvariantCulture)
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(4, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(4, 2), str2)
   End Sub
End Class
'
'This example produces the following results:
'
'str1 = 'MACHINE', str2 = 'machine'
'Ignore case, Turkish culture:
'Substring 'IN' in 'MACHINE' is less than substring 'in' in 'machine'.
'
'Ignore case, invariant culture:
'Substring 'IN' in 'MACHINE' is equal to substring 'in' in 'machine'.
'

注解

要比较的子字符串从 开始,在 中 strA indexAstrB 开始 indexB 。 和 indexA indexB 都从零开始;也就是说,和 中的第一个字符位于位置 strA strB 零,而不是位置 1。 第一个子字符串的长度等于减 strA indexA 1 的长度。 第二个子字符串的长度等于减 strB indexB 1 的长度。

要比较的字符数是两个子字符串 和 的长度中较小 length 者。 、 indexA indexBlength 参数必须无要求。

比较使用 culture 参数获取区域性特定信息,例如大小写规则和单个字符的字母顺序。 例如,区域性可以指定将字符的某些组合视为单个字符,或者以特定方式比较大写和小写字符,或者字符的排序顺序取决于它之前或之后的字符。

比较是使用单词排序规则执行的。 有关单词、字符串和序号排序详细信息,请参阅 System.Globalization.CompareOptions

一个或两个比较项可以是 null 。 根据定义,任何字符串(包括空字符串 ("") )都大于 null 引用;和两个 null 引用的比较结果相等。

当发现不相等或已比较两个子字符串时,比较将终止。 但是,如果两个字符串的比较等于一个字符串的末尾,另一个字符串有剩余字符,则剩余字符的字符串被视为较大。 返回值是上次执行的比较的结果。

当比较受区域性特定的大小写规则影响时,可能会出现意外结果。 例如,在土耳其语中,以下示例生成错误的结果,因为土耳其语中的文件系统不会对"file"中的字母"i"使用语言大小写规则。

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

使用序号比较将路径名称与"file"进行比较。 要执行此操作的正确代码如下所示:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

调用方说明

字符集包括可忽略字符。 Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)方法执行语言或区分区域性的比较时不考虑这些字符。 若要识别比较中的可忽略字符,请调用 Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions) 方法,为 参数提供 OrdinalOrdinalIgnoreCase options 值。

另请参阅

适用于

Compare(String, Int32, String, Int32, Int32, StringComparison)

使用指定的规则比较两个指定的 String 对象的子字符串,并返回一个整数,指示二者在排序顺序中的相对位置。

public:
 static int Compare(System::String ^ strA, int indexA, System::String ^ strB, int indexB, int length, StringComparison comparisonType);
public static int Compare (string strA, int indexA, string strB, int indexB, int length, StringComparison comparisonType);
public static int Compare (string? strA, int indexA, string? strB, int indexB, int length, StringComparison comparisonType);
static member Compare : string * int * string * int * int * StringComparison -> int
Public Shared Function Compare (strA As String, indexA As Integer, strB As String, indexB As Integer, length As Integer, comparisonType As StringComparison) As Integer

参数

strA
String

要在比较中使用的第一个字符串。

indexA
Int32

strA 中子字符串的位置。

strB
String

要在比较中使用的第二个字符串。

indexB
Int32

strB 中子字符串的位置。

length
Int32

要比较的子字符串中字符的最大数量。

comparisonType
StringComparison

一个枚举值,用于指定比较中要使用的规则。

返回

Int32

一个 32 位带符号整数,指示两个比较数之间的词法关系。

“值” 条件
小于零 strA 中的子字符串在排序顺序中位于 strB 中的子字符串之前。
子字符串在排序顺序中出现的位置相同,或 length 参数为零。
大于零 strA 中的子字符串在排序顺序中位于 strB 中的子字符串之后。

例外

indexA 大于 strA.Length

  • 或 -

indexB 大于 strB.Length

  • 或 -

indexAindexBlength 为负数。

  • 或 -

indexAindexBnull,并且 length 大于零。

comparisonType 不是 StringComparison 值。

示例

下面的示例比较两个子字符串。

// Sample for String::Compare(String, Int32, String, Int32, Int32)
using namespace System;
int main()
{
   
   //                0123456
   String^ str1 = "machine";
   String^ str2 = "device";
   String^ str;
   int result;
   Console::WriteLine();
   Console::WriteLine( "str1 = '{0}', str2 = '{1}'", str1, str2 );
   result = String::Compare( str1, 2, str2, 0, 2 );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in ' {1}' is ", str1->Substring( 2, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in ' {1}'.", str2->Substring( 0, 2 ), str2 );
}

/*
This example produces the following results:

str1 = 'machine', str2 = 'device'
Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
*/
String str1 = "machine";
String str2 = "device";
String str;
int result;

Console.WriteLine();
Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2);
result = String.Compare(str1, 2, str2, 0, 2);
str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1);
Console.Write("{0} ", str);
Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(0, 2), str2);

/*
This example produces the following results:

str1 = 'machine', str2 = 'device'
Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
*/
' Sample for String.Compare(String, Int32, String, Int32, Int32)
Class Sample
   Public Shared Sub Main()
      '                       0123456
      Dim str1 As [String] = "machine"
      Dim str2 As [String] = "device"
      Dim str As [String]
      Dim result As Integer
      
      Console.WriteLine()
      Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2)
      result = [String].Compare(str1, 2, str2, 0, 2)
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(0, 2), str2)
   End Sub
End Class
'
'This example produces the following results:
'
'str1 = 'machine', str2 = 'device'
'Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
'

注解

要比较的子字符串 strAindexA 和中的开始 strBindexBindexAindexB 都是从零开始的; 即,和中的第一个字符位于 strA strB 位置零,而不是位置1。 第一个子字符串的长度等于 strA 减号 indexA 加1的长度。 第二个子字符串的长度等于 strB 减号 indexB 加1。

要比较的字符数是两个子字符串的长度中较小的一个和 lengthindexAindexBlength 参数必须为非负。

comparisonType参数指示比较应使用当前的或固定的区域性,是接受还是忽略比较规则的大小写,还是使用 word (区分区域性的) 或序号 (不区分区域性的) 排序规则。

其中一个或两个比较字可以为 null 。 按照定义,包含空字符串 ( "" ) 中的任何字符串都会比较大于 null 引用;和两个 null 引用的比较结果相等。

当发现不相等或比较两个子字符串时,将终止比较。 但是,如果两个字符串的比较结果等于一个字符串的末尾,而另一个字符串还剩个字符,则包含剩余字符的字符串将被视为更大的字符串。 返回值是执行的最后一次比较的结果。

当比较受区域性特定的大小写规则影响时,可能会出现意外的结果。 例如,在土耳其语中,以下示例产生了错误的结果,因为土耳其语中的文件系统不会将语言大小写规则用于 "file" 中的字母 "i"。

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

使用序号比较将路径名称与 "file" 进行比较。 要执行此操作,正确的代码如下所示:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

调用方说明

字符集包括可忽略字符。 Compare(String, Int32, String, Int32, Int32, StringComparison)方法执行语言或区分区域性的比较时不考虑这些字符。 若要识别比较中的可忽略字符,请为 Ordinal 参数提供 或 OrdinalIgnoreCase comparisonType 值。

另请参阅

适用于

Compare(String, Int32, String, Int32, Int32, Boolean)

比较两个指定的 String 对象的子字符串(忽略或考虑其大小写),并返回一个整数,指示二者在排序顺序中的相对位置。

public:
 static int Compare(System::String ^ strA, int indexA, System::String ^ strB, int indexB, int length, bool ignoreCase);
public static int Compare (string? strA, int indexA, string? strB, int indexB, int length, bool ignoreCase);
public static int Compare (string strA, int indexA, string strB, int indexB, int length, bool ignoreCase);
static member Compare : string * int * string * int * int * bool -> int
Public Shared Function Compare (strA As String, indexA As Integer, strB As String, indexB As Integer, length As Integer, ignoreCase As Boolean) As Integer

参数

strA
String

要在比较中使用的第一个字符串。

indexA
Int32

strA 中子字符串的位置。

strB
String

要在比较中使用的第二个字符串。

indexB
Int32

strB 中子字符串的位置。

length
Int32

要比较的子字符串中字符的最大数量。

ignoreCase
Boolean

若要在比较过程中忽略大小写,则为 true;否则为 false

返回

Int32

一个 32 位带符号整数,指示两个比较数之间的词法关系。

“值” 条件
小于零 strA 中的子字符串在排序顺序中位于 strB 中的子字符串之前。
子字符串在排序顺序中出现的位置相同或 length 为零。
大于零 strA 中的子字符串在排序顺序中位于 strB 中的子字符串之后。

例外

indexA 大于 strA.Length

  • 或 -

indexB 大于 strB.Length

  • 或 -

indexAindexBlength 为负数。

  • 或 -

indexAindexBnull,并且 length 大于零。

示例

下面的示例对两个仅大小写不同的子字符串执行两次比较。 第一个比较忽略大小写,第二个比较考虑用例。

// Sample for String::Compare(String, Int32, String, Int32, Int32, Boolean)
using namespace System;
int main()
{
   
   //                0123456
   String^ str1 = "MACHINE";
   String^ str2 = "machine";
   String^ str;
   int result;
   Console::WriteLine();
   Console::WriteLine( "str1 = '{0}', str2 = '{1}'", str1, str2 );
   Console::WriteLine( "Ignore case:" );
   result = String::Compare( str1, 2, str2, 2, 2, true );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in '{1}' is ", str1->Substring( 2, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in '{1}'.", str2->Substring( 2, 2 ), str2 );
   Console::WriteLine();
   Console::WriteLine( "Honor case:" );
   result = String::Compare( str1, 2, str2, 2, 2, false );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in '{1}' is ", str1->Substring( 2, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in '{1}'.", str2->Substring( 2, 2 ), str2 );
}

/*
This example produces the following results:

str1 = 'MACHINE', str2 = 'machine'
Ignore case:
Substring 'CH' in 'MACHINE' is equal to substring 'ch' in 'machine'.

Honor case:
Substring 'CH' in 'MACHINE' is greater than substring 'ch' in 'machine'.
*/
String str1 = "MACHINE";
String str2 = "machine";
String str;
int result;

Console.WriteLine();
Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2);

Console.WriteLine("Ignore case:");
result = String.Compare(str1, 2, str2, 2, 2, true);
str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1);
Console.Write("{0} ", str);
Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(2, 2), str2);
Console.WriteLine();

Console.WriteLine("Honor case:");
result = String.Compare(str1, 2, str2, 2, 2, false);
str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1);
Console.Write("{0} ", str);
Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(2, 2), str2);

/*
This example produces the following results:

str1 = 'MACHINE', str2 = 'machine'
Ignore case:
Substring 'CH' in 'MACHINE' is equal to substring 'ch' in 'machine'.

Honor case:
Substring 'CH' in 'MACHINE' is greater than substring 'ch' in 'machine'.
*/
' Sample for String.Compare(String, Int32, String, Int32, Int32, Boolean)
Class Sample
   
   Public Shared Sub Main()
      '                       0123456
      Dim str1 As [String] = "MACHINE"
      Dim str2 As [String] = "machine"
      Dim str As [String]
      Dim result As Integer
      
      Console.WriteLine()
      Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2)
      Console.WriteLine("Ignore case:")
      result = [String].Compare(str1, 2, str2, 2, 2, True)
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(2, 2), str2)
      
      Console.WriteLine()
      Console.WriteLine("Honor case:")
      result = [String].Compare(str1, 2, str2, 2, 2, False)
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(2, 2), str2)
   End Sub
End Class
'
'This example produces the following results:
'
'str1 = 'MACHINE', str2 = 'machine'
'Ignore case:
'Substring 'CH' in 'MACHINE' is equal to substring 'ch' in 'machine'.
'
'Honor case:
'Substring 'CH' in 'MACHINE' is greater than substring 'ch' in 'machine'.
'

注解

要比较的子字符串在中的开始 strA indexA ,位于中 strB indexBindexAindexB 都是从零开始的; 即,和中的第一个字符位于 strA strB 位置零。 第一个子字符串的长度等于 strA 减号 indexA 加1的长度。 第二个子字符串的长度等于 strB 减号 indexB 加1。

要比较的字符数是两个子字符串的长度中较小的一个和 lengthindexAindexBlength 参数必须为非负。

比较使用当前区域性来获取特定于区域性的信息,如大小写规则和单个字符的字母顺序。 例如,区域性可以指定将某些字符组合视为单个字符,或以特定方式比较大写和小写字符,或字符的排序顺序取决于其前面或后面的字符。

使用字词排序规则执行比较。 有关 word、字符串和顺序排序的详细信息,请参阅 System.Globalization.CompareOptions

警告

在比较字符串时,应调用 Compare(String, Int32, String, Int32, Int32, StringComparison) 方法,这要求您显式指定方法使用的字符串比较的类型。 有关详细信息,请参阅有关使用字符串的最佳实践

其中一个或两个比较字可以为 null 。 按照定义,包含空字符串 ( "" ) 中的任何字符串都会比较大于 null 引用;和两个 null 引用的比较结果相等。

当发现不相等或比较两个子字符串时,将终止比较。 但是,如果两个字符串的比较结果等于一个字符串的末尾,而另一个字符串还剩个字符,则包含剩余字符的字符串将被视为更大的字符串。 返回值是执行的最后一次比较的结果。

当比较受区域性特定的大小写规则影响时,可能会出现意外的结果。 例如,在土耳其语中,以下示例产生了错误的结果,因为土耳其语中的文件系统不会将语言大小写规则用于 "file" 中的字母 "i"。

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

路径名称需要按固定方式进行比较。 要执行此操作,正确的代码如下所示。

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

调用方说明

字符集包括可忽略字符。 此 Compare(String, Int32, String, Int32, Int32, Boolean) 方法在执行语言或区分区域性的比较时不考虑这些字符。 若要在比较中识别可忽略字符,请调用 Compare(String, Int32, String, Int32, Int32, StringComparison) 方法,并为 Ordinal 参数提供值或 OrdinalIgnoreCase comparisonType

另请参阅

适用于

Compare(String, Int32, String, Int32, Int32)

比较两个指定的 String 对象的子字符串,并返回一个指示二者在排序顺序中的相对位置的整数。

public:
 static int Compare(System::String ^ strA, int indexA, System::String ^ strB, int indexB, int length);
public static int Compare (string strA, int indexA, string strB, int indexB, int length);
public static int Compare (string? strA, int indexA, string? strB, int indexB, int length);
static member Compare : string * int * string * int * int -> int
Public Shared Function Compare (strA As String, indexA As Integer, strB As String, indexB As Integer, length As Integer) As Integer

参数

strA
String

要在比较中使用的第一个字符串。

indexA
Int32

strA 中子字符串的位置。

strB
String

要在比较中使用的第二个字符串。

indexB
Int32

strB 中子字符串的位置。

length
Int32

要比较的子字符串中字符的最大数量。

返回

Int32

一个 32 位有符号整数,指示两个比较数之间的词法关系。

条件
小于零 strA 中的子字符串在排序顺序中位于 strB 中的子字符串之前。
子字符串在排序顺序中出现的位置相同或 length 为零。
大于零 strA 中的子字符串在排序顺序中位于 strB 中的子字符串之后。

例外

indexA 大于 strA.Length

  • 或 -

indexB 大于 strB.Length

  • 或 -

indexAindexBlength 为负数。

  • 或 -

indexAindexBnull,并且 length 大于零。

示例

下面的示例比较两个子字符串。

// Sample for String::Compare(String, Int32, String, Int32, Int32)
using namespace System;
int main()
{
   
   //                0123456
   String^ str1 = "machine";
   String^ str2 = "device";
   String^ str;
   int result;
   Console::WriteLine();
   Console::WriteLine( "str1 = '{0}', str2 = '{1}'", str1, str2 );
   result = String::Compare( str1, 2, str2, 0, 2 );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in ' {1}' is ", str1->Substring( 2, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in ' {1}'.", str2->Substring( 0, 2 ), str2 );
}

/*
This example produces the following results:

str1 = 'machine', str2 = 'device'
Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
*/
String str1 = "machine";
String str2 = "device";
String str;
int result;

Console.WriteLine();
Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2);
result = String.Compare(str1, 2, str2, 0, 2);
str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1);
Console.Write("{0} ", str);
Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(0, 2), str2);

/*
This example produces the following results:

str1 = 'machine', str2 = 'device'
Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
*/
' Sample for String.Compare(String, Int32, String, Int32, Int32)
Class Sample
   Public Shared Sub Main()
      '                       0123456
      Dim str1 As [String] = "machine"
      Dim str2 As [String] = "device"
      Dim str As [String]
      Dim result As Integer
      
      Console.WriteLine()
      Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2)
      result = [String].Compare(str1, 2, str2, 0, 2)
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(0, 2), str2)
   End Sub
End Class
'
'This example produces the following results:
'
'str1 = 'machine', str2 = 'device'
'Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
'

注解

要比较的子字符串 strAindexA 和中的开始 strBindexBindexAindexB 都是从零开始的; 即,和中的第一个字符位于 strA strB 位置零。 第一个子字符串的长度等于 strA 减号 indexA 加1的长度。 第二个子字符串的长度等于 strB 减号 indexB 加1。

要比较的字符数是两个子字符串的长度中较小的一个和 lengthindexAindexBlength 参数必须为非负。

比较使用当前区域性来获取特定于区域性的信息,如大小写规则和单个字符的字母顺序。 例如,区域性可以指定将某些字符组合视为单个字符,或以特定方式比较大写和小写字符,或字符的排序顺序取决于其前面或后面的字符。

使用字词排序规则执行比较。 有关 word、字符串和顺序排序的详细信息,请参阅 System.Globalization.CompareOptions

警告

在比较字符串时,应调用 Compare(String, Int32, String, Int32, Int32, StringComparison) 方法,这要求您显式指定方法使用的字符串比较的类型。 有关详细信息,请参阅有关使用字符串的最佳实践

其中一个或两个比较字可以为 null 。 按照定义,包含空字符串 ( "" ) 中的任何字符串都会比较大于 null 引用;和两个 null 引用的比较结果相等。

当发现不相等或比较两个子字符串时,将终止比较。 但是,如果两个字符串的比较结果等于一个字符串的末尾,而另一个字符串还剩个字符,则包含剩余字符的字符串将被视为更大的字符串。 返回值是执行的最后一次比较的结果。

当比较受区域性特定的大小写规则影响时,可能会出现意外的结果。 例如,在土耳其语中,以下示例产生了错误的结果,因为土耳其语中的文件系统不会将语言大小写规则用于 "file" 中的字母 "i"。

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

使用序号比较将路径名称与 "file" 进行比较。 要执行此操作,正确的代码如下所示:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

调用方说明

字符集包括可忽略字符。 此 Compare(String, Int32, String, Int32, Int32) 方法在执行语言或区分区域性的比较时不考虑这些字符。 若要在比较中识别可忽略字符,请调用 Compare(String, Int32, String, Int32, Int32, StringComparison) 方法,并为 Ordinal 参数提供值或 OrdinalIgnoreCase comparisonType

另请参阅

适用于

Compare(String, String)

比较两个指定的 String 对象,并返回一个指示二者在排序顺序中的相对位置的整数。

public:
 static int Compare(System::String ^ strA, System::String ^ strB);
public static int Compare (string strA, string strB);
public static int Compare (string? strA, string? strB);
static member Compare : string * string -> int
Public Shared Function Compare (strA As String, strB As String) As Integer

参数

strA
String

要比较的第一个字符串。

strB
String

要比较的第二个字符串。

返回

Int32

一个 32 位带符号整数,指示两个比较数之间的词法关系。

“值” 条件
小于零 strA 在排序顺序中位于 strB 之前。
strAstrB 在排序顺序中出现的位置相同。
大于零 strA 在排序顺序中位于 strB 之后。

示例

下面的示例调用 Compare(String, String) 方法来比较三组字符串。

using namespace System;

void main()
{
   // Create upper-case characters from their Unicode code units.
   String^ stringUpper = "\x0041\x0042\x0043";

   // Create lower-case characters from their Unicode code units.
   String^ stringLower = "\x0061\x0062\x0063";

   // Display the strings.
   Console::WriteLine("Comparing '{0}' and '{1}':", 
                      stringUpper, stringLower);

   // Compare the uppercased strings; the result is true.
   Console::WriteLine("The Strings are equal when capitalized? {0}",
                      String::Compare(stringUpper->ToUpper(), stringLower->ToUpper()) == 0 
                                      ? "true" : "false");

   // The previous method call is equivalent to this Compare method, which ignores case.
   Console::WriteLine("The Strings are equal when case is ignored? {0}",
                      String::Compare(stringUpper, stringLower, true) == 0
                                      ? "true" : "false");
}
// The example displays the following output:
//       Comparing 'ABC' and 'abc':
//       The Strings are equal when capitalized? true
//       The Strings are equal when case is ignored? true
// Create upper-case characters from their Unicode code units.
String stringUpper = "\x0041\x0042\x0043";

// Create lower-case characters from their Unicode code units.
String stringLower = "\x0061\x0062\x0063";

// Display the strings.
Console.WriteLine("Comparing '{0}' and '{1}':", 
                stringUpper, stringLower);

// Compare the uppercased strings; the result is true.
Console.WriteLine("The Strings are equal when capitalized? {0}",
                String.Compare(stringUpper.ToUpper(), stringLower.ToUpper()) == 0 
                               ? "true" : "false");

// The previous method call is equivalent to this Compare method, which ignores case.
Console.WriteLine("The Strings are equal when case is ignored? {0}",
                String.Compare(stringUpper, stringLower, true) == 0
                               ? "true" : "false" );

// The example displays the following output:
//       Comparing 'ABC' and 'abc':
//       The Strings are equal when capitalized? true
//       The Strings are equal when case is ignored? true
Public Module Example
   Public Sub Main()
      ' Create upper-case characters from their Unicode code units.
      Dim stringUpper As String = ChrW(&H41) + ChrW(&H42) + ChrW(&H43)

      ' Create lower-case characters from their Unicode code units.
      Dim stringLower As String = ChrW(&H61) + ChrW(&H62) + ChrW(&H63)

      ' Display the strings.
      Console.WriteLine("Comparing '{0}' and '{1}':", 
                        stringUpper, stringLower)

      ' Compare the uppercased strings; the result is true.
      Console.WriteLine("The Strings are equal when capitalized? {0}",
                        If(String.Compare(stringUpper.ToUpper(), stringLower.ToUpper()) = 0, 
                                          "true", "false"))

      ' The previous method call is equivalent to this Compare method, which ignores case.
      Console.WriteLine("The Strings are equal when case is ignored? {0}",
                        If(String.Compare(stringUpper, stringLower, true) = 0,
                                          "true", "false"))
   End Sub
End Module 
' The example displays the following output:
'       Comparing 'ABC' and 'abc':
'       The Strings are equal when capitalized? true
'       The Strings are equal when case is ignored? true

在下面的示例中, ReverseStringComparer 类演示了如何用方法来计算两个字符串 Compare

using namespace System;
using namespace System::Text;
using namespace System::Collections;

ref class ReverseStringComparer: public IComparer
{
public:
   virtual int Compare( Object^ x, Object^ y )
   {
      String^ s1 = dynamic_cast<String^>(x);
      String^ s2 = dynamic_cast<String^>(y);

      //negate the return value to get the reverse order
      return  -String::Compare( s1, s2 );
   }

};

void PrintValues( String^ title, IEnumerable^ myList )
{
   Console::Write( "{0,10}: ", title );
   StringBuilder^ sb = gcnew StringBuilder;
   {
      IEnumerator^ en = myList->GetEnumerator();
      String^ s;
      while ( en->MoveNext() )
      {
         s = en->Current->ToString();
         sb->AppendFormat(  "{0}, ", s );
      }
   }
   sb->Remove( sb->Length - 2, 2 );
   Console::WriteLine( sb );
}

void main()
{
   // Creates and initializes a new ArrayList.
   ArrayList^ myAL = gcnew ArrayList;
   myAL->Add( "Eric" );
   myAL->Add( "Mark" );
   myAL->Add( "Lance" );
   myAL->Add( "Rob" );
   myAL->Add( "Kris" );
   myAL->Add( "Brad" );
   myAL->Add( "Kit" );
   myAL->Add( "Bradley" );
   myAL->Add( "Keith" );
   myAL->Add( "Susan" );

   // Displays the properties and values of the ArrayList.
   Console::WriteLine( "Count: {0}", myAL->Count.ToString() );

   PrintValues( "Unsorted", myAL );

   myAL->Sort();
   PrintValues( "Sorted", myAL );

   myAL->Sort( gcnew ReverseStringComparer );
   PrintValues( "Reverse", myAL );

   array<String^>^names = dynamic_cast<array<String^>^>(myAL->ToArray( String::typeid ));
}
using System;
using System.Text;
using System.Collections;

public class SamplesArrayList  {

    public static void Main()  {
        // Creates and initializes a new ArrayList.
        ArrayList myAL = new ArrayList();
        myAL.Add("Eric");
        myAL.Add("Mark");
        myAL.Add("Lance");
        myAL.Add("Rob");
        myAL.Add("Kris");
        myAL.Add("Brad");
        myAL.Add("Kit");
        myAL.Add("Bradley");
        myAL.Add("Keith");
        myAL.Add("Susan");
    
        // Displays the properties and values of	the	ArrayList.
        Console.WriteLine( "Count: {0}", myAL.Count );
        
        PrintValues ("Unsorted", myAL );
        myAL.Sort();
        PrintValues("Sorted", myAL );
        myAL.Sort(new ReverseStringComparer() );
        PrintValues ("Reverse" , myAL );

        string [] names = (string[]) myAL.ToArray (typeof(string));
    }
    public static void PrintValues(string title, IEnumerable	myList )  {
        Console.Write ("{0,10}: ", title);
        StringBuilder sb = new StringBuilder();
        foreach (string s in myList) {
            sb.AppendFormat( "{0}, ", s);
        }
        sb.Remove (sb.Length-2,2);
        Console.WriteLine(sb);
    }
}
public class ReverseStringComparer : IComparer {
   public int Compare (object x, object y) {
       string s1 = x as string;
       string s2 = y as string;	
       //negate the return value to get the reverse order
       return - String.Compare (s1,s2);
   }
}
Imports System.Text
Imports System.Collections



Public Class SamplesArrayList
    
    
    Public Shared Sub Main()
        Dim myAL As New ArrayList()
        ' Creates and initializes a new ArrayList.
        myAL.Add("Eric")
        myAL.Add("Mark")
        myAL.Add("Lance")
        myAL.Add("Rob")
        myAL.Add("Kris")
        myAL.Add("Brad")
        myAL.Add("Kit")
        myAL.Add("Bradley")
        myAL.Add("Keith")
        myAL.Add("Susan")
        
        ' Displays the properties and values of	the	ArrayList.
        Console.WriteLine("Count: {0}", myAL.Count)
        PrintValues("Unsorted", myAL)
        myAL.Sort()
        PrintValues("Sorted", myAL)
        Dim comp as New ReverseStringComparer
        myAL.Sort(comp)
        PrintValues("Reverse", myAL)

        Dim names As String() = CType(myAL.ToArray(GetType(String)), String())
    End Sub
   
   
    
    Public Shared Sub PrintValues(title As String, myList As IEnumerable)
        Console.Write("{0,10}: ", title)
        Dim sb As New StringBuilder()
        Dim s As String
        For Each s In  myList
            sb.AppendFormat("{0}, ", s)
        Next s
        sb.Remove(sb.Length - 2, 2)
        Console.WriteLine(sb)
    End Sub
End Class

Public Class ReverseStringComparer 
  Implements IComparer
    
     Function Compare(x As Object, y As Object) As Integer implements IComparer.Compare
        Dim s1 As String = CStr (x)
        Dim s2 As String = CStr (y)
        
        'negate the return value to get the reverse order
        Return - [String].Compare(s1, s2)
    
    End Function 'Compare
End Class

注解

比较使用当前区域性来获取特定于区域性的信息,如大小写规则和单个字符的字母顺序。 例如,区域性可以指定将某些字符组合视为单个字符,或以特定方式比较大写和小写字符,或字符的排序顺序取决于其前面或后面的字符。

使用字词排序规则执行比较。 有关 word、字符串和顺序排序的详细信息,请参阅 System.Globalization.CompareOptions

警告

在比较字符串时,应调用 Compare(String, String, StringComparison) 方法,这要求您显式指定方法使用的字符串比较的类型。 有关详细信息,请参阅有关使用字符串的最佳实践

其中一个或两个比较字可以为 null 。 按照定义,包含空字符串 ( "" ) 中的任何字符串都会比较大于 null 引用;和两个 null 引用的比较结果相等。

当发现不相等或已比较两个字符串时,将终止比较。 但是,如果两个字符串的比较结果等于一个字符串的末尾,而另一个字符串还剩个字符,则包含剩余字符的字符串将被视为更大的字符串。 返回值是执行的最后一次比较的结果。

当比较受区域性特定的大小写规则影响时,可能会出现意外的结果。 例如,在土耳其语中,以下示例产生了错误的结果,因为土耳其语中的文件系统不会将语言大小写规则用于 "file" 中的字母 "i"。

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

使用序号比较将路径名称与 "file" 进行比较。 要执行此操作,正确的代码如下所示:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

调用方说明

字符集包括可忽略字符。 Compare(String, String)当方法执行区分区域性的比较时,它不会考虑此类字符。 例如,如果以下代码在 .NET Framework 4 或更高版本上运行,则使用软连字符 (使用 "ani" 的 "动物" 比较区分区域性的比较或 U + 00AD) 指示这两个字符串是等效的。

::: code language = "csharp" source = "~/samples/snippets/csharp/VS_Snippets_CLR_System/system。Compare21 "id =" Snippet21 ":::::: code language =" vb "source =" ~/samples/snippets/visualbasic/VS_Snippets_CLR_System/system。Compare21 "id =" Snippet21 ":::

若要在字符串比较中识别可忽略字符,请调用 Compare(String, String, StringComparison) 方法,并 Ordinal 为参数提供或的值 OrdinalIgnoreCase comparisonType

另请参阅

适用于

Compare(String, String, Boolean, CultureInfo)

比较两个指定的 String 对象(其中忽略或考虑其大小写,并使用区域性特定的信息干预比较),并返回一个整数,指示二者在排序顺序中的相对位置。

public:
 static int Compare(System::String ^ strA, System::String ^ strB, bool ignoreCase, System::Globalization::CultureInfo ^ culture);
public static int Compare (string? strA, string? strB, bool ignoreCase, System.Globalization.CultureInfo? culture);
public static int Compare (string strA, string strB, bool ignoreCase, System.Globalization.CultureInfo culture);
static member Compare : string * string * bool * System.Globalization.CultureInfo -> int
Public Shared Function Compare (strA As String, strB As String, ignoreCase As Boolean, culture As CultureInfo) As Integer

参数

strA
String

要比较的第一个字符串。

strB
String

要比较的第二个字符串。

ignoreCase
Boolean

若要在比较过程中忽略大小写,则为 true;否则为 false

culture
CultureInfo

一个对象,提供区域性特定的比较信息。 如果 culturenull,则使用当前区域性。

返回

Int32

一个 32 位带符号整数,指示两个比较数之间的词法关系。

“值” 条件
小于零 strA 在排序顺序中位于 strB 之前。
strAstrB 在排序顺序中出现的位置相同。
大于零 strA 在排序顺序中位于 strB 之后。

示例

下面的示例演示区域性如何影响比较。 在捷克语-捷克语,"ch" 是大于 "d" 的单个字符。 但是,在英语美国区域性中,"ch" 包含两个字符,"c" 小于 "d"。

using namespace System;
using namespace System::Globalization;
String^ symbol( int r )
{
   String^ s = "=";
   if ( r < 0 )
      s = "<";
   else
   if ( r > 0 )
      s = ">";


   return s;
}

int main()
{
   String^ str1 = "change";
   String^ str2 = "dollar";
   String^ relation = nullptr;
   relation = symbol( String::Compare( str1, str2, false, gcnew CultureInfo( "en-US" ) ) );
   Console::WriteLine( "For en-US: {0} {1} {2}", str1, relation, str2 );
   relation = symbol( String::Compare( str1, str2, false, gcnew CultureInfo( "cs-CZ" ) ) );
   Console::WriteLine( "For cs-CZ: {0} {1} {2}", str1, relation, str2 );
}

/*
This example produces the following results.
For en-US: change < dollar
For cs-CZ: change > dollar
*/
public static void Main()
{
    String str1 = "change";
    String str2 = "dollar";
    String relation = null;

    relation = symbol(String.Compare(str1, str2, false, new CultureInfo("en-US")));
    Console.WriteLine("For en-US: {0} {1} {2}", str1, relation, str2);

    relation = symbol(String.Compare(str1, str2, false, new CultureInfo("cs-CZ")));
    Console.WriteLine("For cs-CZ: {0} {1} {2}", str1, relation, str2);
}

private static String symbol(int r)
{
    String s = "=";
    if (r < 0) s = "<";
    else if (r > 0) s = ">";
    return s;
}

/*
This example produces the following results.
For en-US: change < dollar
For cs-CZ: change > dollar
*/
Imports System.Globalization
 _

Class Sample
   Public Shared Sub Main()
      Dim str1 As [String] = "change"
      Dim str2 As [String] = "dollar"
      Dim relation As [String] = Nothing
      
      relation = symbol([String].Compare(str1, str2, False, New CultureInfo("en-US")))
      Console.WriteLine("For en-US: {0} {1} {2}", str1, relation, str2)
      
      relation = symbol([String].Compare(str1, str2, False, New CultureInfo("cs-CZ")))
      Console.WriteLine("For cs-CZ: {0} {1} {2}", str1, relation, str2)
   End Sub
   
   Private Shared Function symbol(r As Integer) As [String]
      Dim s As [String] = "="
      If r < 0 Then
         s = "<"
      Else
         If r > 0 Then
            s = ">"
         End If
      End If
      Return s
   End Function 'symbol
End Class
'
'This example produces the following results.
'For en-US: change < dollar
'For cs-CZ: change > dollar
'

注解

该比较使用 culture 参数获取特定于区域性的信息,如大小写规则和单个字符的字母顺序。 例如,区域性可以指定将某些字符组合视为单个字符,或以特定方式比较大写和小写字符,或字符的排序顺序取决于其前面或后面的字符。

使用字词排序规则执行比较。 有关 word、字符串和顺序排序的详细信息,请参阅 System.Globalization.CompareOptions

其中一个或两个比较字可以为 null 。 按照定义,包含空字符串 ( "" ) 中的任何字符串都会比较大于 null 引用;和两个 null 引用的比较结果相等。

当发现不相等或已比较两个字符串时,将终止比较。 但是,如果两个字符串的比较结果等于一个字符串的末尾,而另一个字符串还剩个字符,则包含剩余字符的字符串将被视为更大的字符串。 返回值是执行的最后一次比较的结果。

当比较受区域性特定的大小写规则影响时,可能会出现意外的结果。 例如,在土耳其语中,以下示例产生了错误的结果,因为土耳其语中的文件系统不会将语言大小写规则用于 "file" 中的字母 "i"。

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

使用序号比较将路径名称与 "file" 进行比较。 要执行此操作,正确的代码如下所示:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

调用方说明

字符集包括可忽略字符。 Compare(String, String, Boolean, CultureInfo)当方法执行区分区域性的比较时,它不会考虑此类字符。 例如,如果以下代码在 .NET Framework 4 或更高版本上运行,则使用软连字符 (不区分大小写的 "动物" 比较使用软连字符,或使用固定区域性的 U + 00AD) 指示这两个字符串是等效的。

::: code language = "csharp" source = "~/samples/snippets/csharp/VS_Snippets_CLR_System/system。Compare23 "id =" Snippet23 ":::::: code language =" vb "source =" ~/samples/snippets/visualbasic/VS_Snippets_CLR_System/system。Compare23 "id =" Snippet23 ":::

若要在字符串比较中识别可忽略字符,请调用 Compare(String, String, CultureInfo, CompareOptions) 方法,并 Ordinal 为参数提供或的值 OrdinalIgnoreCase options

另请参阅

适用于

Compare(String, String, StringComparison)

使用指定的规则比较两个指定的 String 对象,并返回一个整数,指示二者在排序顺序中的相对位置。

public:
 static int Compare(System::String ^ strA, System::String ^ strB, StringComparison comparisonType);
public static int Compare (string strA, string strB, StringComparison comparisonType);
public static int Compare (string? strA, string? strB, StringComparison comparisonType);
static member Compare : string * string * StringComparison -> int
Public Shared Function Compare (strA As String, strB As String, comparisonType As StringComparison) As Integer

参数

strA
String

要比较的第一个字符串。

strB
String

要比较的第二个字符串。

comparisonType
StringComparison

一个枚举值,用于指定比较中要使用的规则。

返回

Int32

一个 32 位带符号整数,指示两个比较数之间的词法关系。

“值” 条件
小于零 strA 在排序顺序中位于 strB 之前。
strAstrB 在排序顺序中的位置相同。
大于零 strA 在排序顺序中位于 strB 之后。

例外

comparisonType 不是 StringComparison 值。

示例

下面的示例比较字母 "I" 的三个版本。 结果受区域性选择的影响,是否忽略大小写,以及是否执行序号比较。

// This example demonstrates the
// System.String.Compare(String, String, StringComparison) method.

using namespace System;
using namespace System::Threading;

void Test(int testStringIndex, int searchStringIndex, 
          StringComparison comparison, array<String^>^ testI, 
          array<String^>^ testNames)
{
    String^ resultFormat = "{0} is {1} {2}";
    String^ resultString = "equal to";
    int comparisonValue = 0;

    comparisonValue = String::Compare(testI[testStringIndex],
        testI[searchStringIndex], comparison);
    if (comparisonValue < 0)
    {
        resultString = "less than";
    }
    else if (comparisonValue > 0)
    {
        resultString = "greater than";
    }
    Console::WriteLine(resultFormat, testNames[testStringIndex], resultString,
        testNames[searchStringIndex]);
}

int main()
{
    String^ introMessage =
        "Compare three versions of the letter I using different " +
        "values of StringComparison.";

    // Define an array of strings where each element contains a version of
    // the letter I. (An array of strings is used so you can easily modify
    // this code example to test additional or different combinations of
    // strings.)

    array<String^>^ letterVariation = gcnew array<String^>(3);
    // LATIN SMALL LETTER I (U+0069)
    letterVariation[0] = "i";
    // LATIN SMALL LETTER DOTLESS I (U+0131)
    letterVariation[1] = L"\u0131";
    // LATIN CAPITAL LETTER I (U+0049)
    letterVariation[2] = "I";

    array<String^>^ unicodeNames = {
        "LATIN SMALL LETTER I (U+0069)",
        "LATIN SMALL LETTER DOTLESS I (U+0131)",
        "LATIN CAPITAL LETTER I (U+0049)"};

    array<StringComparison>^ comparisonValues = {
        StringComparison::CurrentCulture,
        StringComparison::CurrentCultureIgnoreCase,
        StringComparison::InvariantCulture,
        StringComparison::InvariantCultureIgnoreCase,
        StringComparison::Ordinal,
        StringComparison::OrdinalIgnoreCase};

    Console::Clear();
    Console::WriteLine(introMessage);

    // Display the current culture because the culture-specific comparisons
    // can produce different results with different cultures.
    Console::WriteLine("The current culture is {0}.{1}",
        Thread::CurrentThread->CurrentCulture->Name, Environment::NewLine);

    // Determine the relative sort order of three versions of the letter I.
    for each (StringComparison stringCmp in comparisonValues)
    {
        Console::WriteLine("StringComparison.{0}:", stringCmp);

        // LATIN SMALL LETTER I (U+0069) : LATIN SMALL LETTER DOTLESS I
        // (U+0131)
        Test(0, 1, stringCmp, letterVariation, unicodeNames);

        // LATIN SMALL LETTER I (U+0069) : LATIN CAPITAL LETTER I (U+0049)
        Test(0, 2, stringCmp, letterVariation, unicodeNames);

        // LATIN SMALL LETTER DOTLESS I (U+0131) : LATIN CAPITAL LETTER I
        // (U+0049)
        Test(1, 2, stringCmp, letterVariation, unicodeNames);

        Console::WriteLine();
    }
}

/*
This code example produces the following results:

Compare three versions of the letter I using different values of 
StringComparison.
The current culture is en-US.

StringComparison.CurrentCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

StringComparison.CurrentCultureIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

StringComparison.InvariantCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

StringComparison.InvariantCultureIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

StringComparison.Ordinal:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is greater than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

StringComparison.OrdinalIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

*/
// This example demonstrates the 
// System.String.Compare(String, String, StringComparison) method.

using System;
using System.Threading;

class Sample 
{
    public static void Main() 
    {
        string intro = "Compare three versions of the letter I using different " + 
                       "values of StringComparison.";

        // Define an array of strings where each element contains a version of the 
        // letter I. (An array of strings is used so you can easily modify this 
        // code example to test additional or different combinations of strings.)  

        string[] threeIs = new string[3];
        // LATIN SMALL LETTER I (U+0069)
        threeIs[0] = "\u0069";
        // LATIN SMALL LETTER DOTLESS I (U+0131)
        threeIs[1] = "\u0131";
        // LATIN CAPITAL LETTER I (U+0049)
        threeIs[2] = "\u0049";

        string[] unicodeNames = 
        {
            "LATIN SMALL LETTER I (U+0069)", 
            "LATIN SMALL LETTER DOTLESS I (U+0131)", 
            "LATIN CAPITAL LETTER I (U+0049)"
        };

        StringComparison[] scValues =
        {
            StringComparison.CurrentCulture,
            StringComparison.CurrentCultureIgnoreCase,
            StringComparison.InvariantCulture,
            StringComparison.InvariantCultureIgnoreCase,
            StringComparison.Ordinal,
            StringComparison.OrdinalIgnoreCase
        };

        Console.Clear();
        Console.WriteLine(intro);

        // Display the current culture because the culture-specific comparisons
        // can produce different results with different cultures.
        Console.WriteLine(
            "The current culture is {0}.\n", Thread.CurrentThread.CurrentCulture.Name);

        // Determine the relative sort order of three versions of the letter I. 
        foreach (StringComparison sc in scValues)
        {
            Console.WriteLine("StringComparison.{0}:", sc);

            // LATIN SMALL LETTER I (U+0069) : LATIN SMALL LETTER DOTLESS I (U+0131)
            Test(0, 1, sc, threeIs, unicodeNames);

            // LATIN SMALL LETTER I (U+0069) : LATIN CAPITAL LETTER I (U+0049)
            Test(0, 2, sc, threeIs, unicodeNames);

            // LATIN SMALL LETTER DOTLESS I (U+0131) : LATIN CAPITAL LETTER I (U+0049)
            Test(1, 2, sc, threeIs, unicodeNames);

            Console.WriteLine();
        }
    }

    protected static void Test(
        int x, int y, StringComparison comparison, string[] testI, string[] testNames)
    {
        string resultFmt = "{0} is {1} {2}";
        string result = "equal to";
        int cmpValue = 0;

        cmpValue = String.Compare(testI[x], testI[y], comparison);
        if (cmpValue < 0)
            result = "less than";
        else if (cmpValue > 0)
            result = "greater than";
        Console.WriteLine(resultFmt, testNames[x], result, testNames[y]);
    }
}

/*
This code example produces the following results:

Compare three versions of the letter I using different values of StringComparison.
The current culture is en-US.

StringComparison.CurrentCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.CurrentCultureIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.InvariantCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.InvariantCultureIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.Ordinal:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is greater than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.OrdinalIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

*/
' This example demonstrates the 
' System.String.Compare(String, String, StringComparison) method.

Imports System.Threading

Class Sample
    Public Shared Sub Main() 
        Dim intro As String = "Compare three versions of the letter I using different " & _
                              "values of StringComparison."
        
        ' Define an array of strings where each element contains a version of the 
        ' letter I. (An array of strings is used so you can easily modify this 
        ' code example to test additional or different combinations of strings.)  
        Dim threeIs(2) As String
        ' LATIN SMALL LETTER I (U+0069)
        threeIs(0) = "i"
        ' LATIN SMALL LETTER DOTLESS I (U+0131)
        threeIs(1) = "ı"
        ' LATIN CAPITAL LETTER I (U+0049)
        threeIs(2) = "I"
        
        Dim unicodeNames As String() =  { _
                            "LATIN SMALL LETTER I (U+0069)", _
                            "LATIN SMALL LETTER DOTLESS I (U+0131)", _
                            "LATIN CAPITAL LETTER I (U+0049)" }
        
        Dim scValues As StringComparison() =  { _
                            StringComparison.CurrentCulture, _
                            StringComparison.CurrentCultureIgnoreCase, _
                            StringComparison.InvariantCulture, _
                            StringComparison.InvariantCultureIgnoreCase, _
                            StringComparison.Ordinal, _
                            StringComparison.OrdinalIgnoreCase }
        '
        Console.Clear()
        Console.WriteLine(intro)
        
        ' Display the current culture because the culture-specific comparisons
        ' can produce different results with different cultures.
        Console.WriteLine("The current culture is {0}." & vbCrLf, _
                           Thread.CurrentThread.CurrentCulture.Name)
        
        ' Determine the relative sort order of three versions of the letter I. 
        Dim sc As StringComparison
        For Each sc In  scValues
            Console.WriteLine("StringComparison.{0}:", sc)
            
            ' LATIN SMALL LETTER I (U+0069) : LATIN SMALL LETTER DOTLESS I (U+0131)
            Test(0, 1, sc, threeIs, unicodeNames)
            
            ' LATIN SMALL LETTER I (U+0069) : LATIN CAPITAL LETTER I (U+0049)
            Test(0, 2, sc, threeIs, unicodeNames)
            
            ' LATIN SMALL LETTER DOTLESS I (U+0131) : LATIN CAPITAL LETTER I (U+0049)
            Test(1, 2, sc, threeIs, unicodeNames)
            
            Console.WriteLine()
        Next sc
    
    End Sub
    
    Protected Shared Sub Test(ByVal x As Integer, ByVal y As Integer, _
                              ByVal comparison As StringComparison, _
                              ByVal testI() As String, ByVal testNames() As String) 
        Dim resultFmt As String = "{0} is {1} {2}"
        Dim result As String = "equal to"
        Dim cmpValue As Integer = 0
        '
        cmpValue = String.Compare(testI(x), testI(y), comparison)
        If cmpValue < 0 Then
            result = "less than"
        ElseIf cmpValue > 0 Then
            result = "greater than"
        End If
        Console.WriteLine(resultFmt, testNames(x), result, testNames(y))
    
    End Sub
End Class

'
'This code example produces the following results:
'
'Compare three versions of the letter I using different values of StringComparison.
'The current culture is en-US.
'
'StringComparison.CurrentCulture:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'
'StringComparison.CurrentCultureIgnoreCase:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'
'StringComparison.InvariantCulture:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'
'StringComparison.InvariantCultureIgnoreCase:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'
'StringComparison.Ordinal:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is greater than LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'
'StringComparison.OrdinalIgnoreCase:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'

注解

comparisonType参数指示比较应使用当前的或固定的区域性,是接受还是忽略比较规则的大小写,还是使用 word (区分区域性的) 或序号 (不区分区域性的) 排序规则。

其中一个或两个比较字可以为 null 。 按照定义,包含空字符串 ( "" ) 中的任何字符串都会比较大于 null 引用;和两个 null 引用的比较结果相等。

当发现不相等或已比较两个字符串时,将终止比较。 但是,如果两个字符串的比较结果等于一个字符串的末尾,而另一个字符串还剩个字符,则包含剩余字符的字符串将被视为更大的字符串。 返回值是执行的最后一次比较的结果。

当比较受区域性特定的大小写规则影响时,可能会出现意外的结果。 例如,在土耳其语中,以下示例产生了错误的结果,因为土耳其语中的文件系统不会将语言大小写规则用于 "file" 中的字母 "i"。

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

使用序号比较将路径名称与 "file" 进行比较。 要执行此操作,正确的代码如下所示:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

调用方说明

字符集包括可忽略字符。 Compare(String, String, StringComparison)当方法执行区分区域性的比较时,它不会考虑此类字符。 若要在比较中识别可忽略字符,请 Ordinal 为参数提供值或 OrdinalIgnoreCase comparisonType

另请参阅

适用于

Compare(String, String, Boolean)

比较两个指定的 String 对象(其中忽略或考虑其大小写),并返回一个整数,指示二者在排序顺序中的相对位置。

public:
 static int Compare(System::String ^ strA, System::String ^ strB, bool ignoreCase);
public static int Compare (string strA, string strB, bool ignoreCase);
public static int Compare (string? strA, string? strB, bool ignoreCase);
static member Compare : string * string * bool -> int
Public Shared Function Compare (strA As String, strB As String, ignoreCase As Boolean) As Integer

参数

strA
String

要比较的第一个字符串。

strB
String

要比较的第二个字符串。

ignoreCase
Boolean

若要在比较过程中忽略大小写,则为 true;否则为 false

返回

Int32

一个 32 位带符号整数,指示两个比较数之间的词法关系。

“值” 条件
小于零 strA 在排序顺序中位于 strB 之前。
strAstrB 在排序顺序中出现的位置相同。
大于零 strA 在排序顺序中位于 strB 之后。

示例

下面的示例演示 Compare(String, String, Boolean) 方法等效于在 ToUpper ToLower 比较字符串时使用或。

using namespace System;

void main()
{
   // Create upper-case characters from their Unicode code units.
   String^ stringUpper = "\x0041\x0042\x0043";

   // Create lower-case characters from their Unicode code units.
   String^ stringLower = "\x0061\x0062\x0063";

   // Display the strings.
   Console::WriteLine("Comparing '{0}' and '{1}':", 
                      stringUpper, stringLower);

   // Compare the uppercased strings; the result is true.
   Console::WriteLine("The Strings are equal when capitalized? {0}",
                      String::Compare(stringUpper->ToUpper(), stringLower->ToUpper()) == 0 
                                      ? "true" : "false");

   // The previous method call is equivalent to this Compare method, which ignores case.
   Console::WriteLine("The Strings are equal when case is ignored? {0}",
                      String::Compare(stringUpper, stringLower, true) == 0
                                      ? "true" : "false");
}
// The example displays the following output:
//       Comparing 'ABC' and 'abc':
//       The Strings are equal when capitalized? true
//       The Strings are equal when case is ignored? true
// Create upper-case characters from their Unicode code units.
String stringUpper = "\x0041\x0042\x0043";

// Create lower-case characters from their Unicode code units.
String stringLower = "\x0061\x0062\x0063";

// Display the strings.
Console.WriteLine("Comparing '{0}' and '{1}':", 
                stringUpper, stringLower);

// Compare the uppercased strings; the result is true.
Console.WriteLine("The Strings are equal when capitalized? {0}",
                String.Compare(stringUpper.ToUpper(), stringLower.ToUpper()) == 0 
                               ? "true" : "false");

// The previous method call is equivalent to this Compare method, which ignores case.
Console.WriteLine("The Strings are equal when case is ignored? {0}",
                String.Compare(stringUpper, stringLower, true) == 0
                               ? "true" : "false" );

// The example displays the following output:
//       Comparing 'ABC' and 'abc':
//       The Strings are equal when capitalized? true
//       The Strings are equal when case is ignored? true
Public Module Example
   Public Sub Main()
      ' Create upper-case characters from their Unicode code units.
      Dim stringUpper As String = ChrW(&H41) + ChrW(&H42) + ChrW(&H43)

      ' Create lower-case characters from their Unicode code units.
      Dim stringLower As String = ChrW(&H61) + ChrW(&H62) + ChrW(&H63)

      ' Display the strings.
      Console.WriteLine("Comparing '{0}' and '{1}':", 
                        stringUpper, stringLower)

      ' Compare the uppercased strings; the result is true.
      Console.WriteLine("The Strings are equal when capitalized? {0}",
                        If(String.Compare(stringUpper.ToUpper(), stringLower.ToUpper()) = 0, 
                                          "true", "false"))

      ' The previous method call is equivalent to this Compare method, which ignores case.
      Console.WriteLine("The Strings are equal when case is ignored? {0}",
                        If(String.Compare(stringUpper, stringLower, true) = 0,
                                          "true", "false"))
   End Sub
End Module 
' The example displays the following output:
'       Comparing 'ABC' and 'abc':
'       The Strings are equal when capitalized? true
'       The Strings are equal when case is ignored? true

注解

比较使用当前区域性来获取特定于区域性的信息,如大小写规则和单个字符的字母顺序。 例如,区域性可以指定将某些字符组合视为单个字符,或以特定方式比较大写和小写字符,或字符的排序顺序取决于其前面或后面的字符。

使用字词排序规则执行比较。 有关 word、字符串和顺序排序的详细信息,请参阅 System.Globalization.CompareOptions

警告

在比较字符串时,应调用 Compare(String, String, StringComparison) 方法,这要求您显式指定方法使用的字符串比较的类型。 有关详细信息,请参阅有关使用字符串的最佳实践

其中一个或两个比较字可以为 null 。 按照定义,包含空字符串 ( "" ) 中的任何字符串都会比较大于 null 引用;和两个 null 引用的比较结果相等。

当发现不相等或已比较两个字符串时,将终止比较。 但是,如果两个字符串的比较结果等于一个字符串的末尾,而另一个字符串还剩个字符,则包含剩余字符的字符串将被视为更大的字符串。 返回值是执行的最后一次比较的结果。

当比较受区域性特定的大小写规则影响时,可能会出现意外的结果。 例如,在土耳其语中,以下示例产生了错误的结果,因为土耳其语中的文件系统不会将语言大小写规则用于 "file" 中的字母 "i"。

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

使用序号比较将路径名称与 "file" 进行比较。 要执行此操作,正确的代码如下所示:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}
static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}
Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

调用方说明

字符集包括可忽略字符。 Compare(String, String, Boolean)当方法执行区分区域性的比较时,它不会考虑此类字符。 例如,如果以下代码在 .NET Framework 4 或更高版本上运行,则使用软连字符的 "动物" (区分区域性、不区分大小写的 "动物" 比较,或使用 U + 00AD) 指示这两个字符串是等效的。

::: code language = "csharp" source = "~/samples/snippets/csharp/VS_Snippets_CLR_System/system。Compare22 "id =" Snippet22 ":::::: code language =" vb "source =" ~/samples/snippets/visualbasic/VS_Snippets_CLR_System/system。Compare22 "id =" Snippet22 ":::

若要在字符串比较中识别可忽略字符,请调用 Compare(String, String, StringComparison) 方法,并 Ordinal 为参数提供或的值 OrdinalIgnoreCase comparisonType

另请参阅

适用于

Compare(String, String, CultureInfo, CompareOptions)

对两个指定的 String 对象进行比较,使用指定的比较选项和区域性特定的信息来影响比较,并返回一个整数,该整数指示这两个字符串在排序顺序中的关系。

public:
 static int Compare(System::String ^ strA, System::String ^ strB, System::Globalization::CultureInfo ^ culture, System::Globalization::CompareOptions options);
public static int Compare (string? strA, string? strB, System.Globalization.CultureInfo? culture, System.Globalization.CompareOptions options);
public static int Compare (string strA, string strB, System.Globalization.CultureInfo culture, System.Globalization.CompareOptions options);
static member Compare : string * string * System.Globalization.CultureInfo * System.Globalization.CompareOptions -> int
Public Shared Function Compare (strA As String, strB As String, culture As CultureInfo, options As CompareOptions) As Integer

参数

strA
String

要比较的第一个字符串。

strB
String

要比较的第二个字符串。

culture
CultureInfo

提供区域性特定的比较信息的区域性。 如果 culturenull,则使用当前区域性。

options
CompareOptions

要在执行比较时使用的选项(如忽略大小写或符号)。

返回

Int32

一个 32 位带符号整数,该整数指示 strAstrB 之间的词法关系,如下表所示

“值” 条件
小于零 strA 在排序顺序中位于 strB 之前。
strAstrB 在排序顺序中出现的位置相同。
大于零 strA 在排序顺序中位于 strB 之后。

例外

options 不是 CompareOptions 值。

示例

下面的示例以三种不同的方式对两个字符串进行比较:对 en-us 区域性使用语言比较;对于 en-us 区域性,使用区分语言区分大小写的比较;和使用序号比较。 它说明了这三种比较方法如何产生三个不同的结果。

using namespace System;
using namespace System::Globalization;

public ref class Example
{
public:
   static void Main()
   {
      String^ string1 = "brother";
      String^ string2 = "Brother";
      String^ relation;
      int result;

      // Cultural (linguistic) comparison.
      result = String::Compare(string1, string2, gcnew CultureInfo("en-US"),
                              CompareOptions::None);
      if (result > 0)
         relation = "comes after";
      else if (result == 0)
         relation = "is the same as";
      else
         relation = "comes before";

      Console::WriteLine("'{0}' {1} '{2}'.",
                        string1, relation, string2);

      // Cultural (linguistic) case-insensitive comparison.
      result = String::Compare(string1, string2, gcnew CultureInfo("en-US"),
                              CompareOptions::IgnoreCase);
      if (result > 0)
         relation = "comes after";
      else if (result == 0)
         relation = "is the same as";
      else
         relation = "comes before";

      Console::WriteLine("'{0}' {1} '{2}'.",
                        string1, relation, string2);

       // Culture-insensitive ordinal comparison.
      result = String::CompareOrdinal(string1, string2);
      if (result > 0)
         relation = "comes after";
      else if (result == 0)
         relation = "is the same as";
      else
         relation = "comes before";

      Console::WriteLine("'{0}' {1} '{2}'.",
                        string1, relation, string2);
   }
};

int main()
{
    Example::Main();
}


// The example produces the following output:
//    'brother' comes before 'Brother'.
//    'brother' is the same as 'Brother'.
//    'brother' comes after 'Brother'.
using System;
using System.Globalization;

public class Example
{
    public static void Main()
    {
        string string1 = "brother";
        string string2 = "Brother";
        string relation;
        int result;

        // Cultural (linguistic) comparison.
        result = String.Compare(string1, string2, new CultureInfo("en-US"), 
                              CompareOptions.None);
        if (result > 0)
            relation = "comes after";
        else if (result == 0)
            relation = "is the same as";
        else
            relation = "comes before";

        Console.WriteLine("'{0}' {1} '{2}'.", 
                        string1, relation, string2);

        // Cultural (linguistic) case-insensitive comparison.
        result = String.Compare(string1, string2, new CultureInfo("en-US"), 
                              CompareOptions.IgnoreCase);
        if (result > 0)
            relation = "comes after";
        else if (result == 0)
            relation = "is the same as";
        else
            relation = "comes before";

        Console.WriteLine("'{0}' {1} '{2}'.", 
                        string1, relation, string2);
 
        // Culture-insensitive ordinal comparison.
        result = String.CompareOrdinal(string1, string2);
        if (result > 0)
            relation = "comes after";
        else if (result == 0)
            relation = "is the same as";
        else
            relation = "comes before";

        Console.WriteLine("'{0}' {1} '{2}'.", 
                        string1, relation, string2);

        // The example produces the following output:
        //    'brother' comes before 'Brother'.   
        //    'brother' is the same as 'Brother'.
        //    'brother' comes after 'Brother'.
    }
}
Imports System.Globalization

Public Module Example
   Public Sub Main()
      Dim string1 As String = "brother"
      Dim string2 As String = "Brother"
      Dim relation As String
      Dim result As Integer

      ' Cultural (linguistic) comparison.
      result = String.Compare(string1, string2, _
                              New CultureInfo("en-US"), CompareOptions.None)
      If result > 0 Then
         relation = "comes after"
      ElseIf result = 0 Then
         relation = "is the same as"
      Else
         relation = "comes before"
      End If
      Console.WriteLine("'{0}' {1} '{2}'.", string1, relation, string2)

      ' Cultural (linguistic) case-insensitive comparison.
      result = String.Compare(string1, string2, _
                              New CultureInfo("en-US"), CompareOptions.IgnoreCase)
      If result > 0 Then
         relation = "comes after"
      ElseIf result = 0 Then
         relation = "is the same as"
      Else
         relation = "comes before"
      End If
      Console.WriteLine("'{0}' {1} '{2}'.", string1, relation, string2)

      ' Culture-insensitive ordinal comparison.
      result = String.CompareOrdinal(string1, string2)
      If result > 0 Then
         relation = "comes after"
      ElseIf result = 0 Then
         relation = "is the same as"
      Else
         relation = "comes before"
      End If
      Console.WriteLine("'{0}' {1} '{2}'.", string1, relation, string2)
   End Sub
End Module
' The example produces the following output:
'    'brother' comes before 'Brother'.   
'    'brother' is the same as 'Brother'.
'    'brother' comes after 'Brother'.

注解

该比较使用 culture 参数获取特定于区域性的信息,如大小写规则和单个字符的字母顺序。 例如,特定的区域性可以指定将某些字符组合视为单个字符、以特定方式进行比较的大写和小写字符,或字符的排序顺序取决于其前面或后面的字符。

注意

Compare(String, String, CultureInfo, CompareOptions) 方法主要用于排序或 alphabetizing 操作。 当方法调用的主要目的是确定两个字符串是否等效时,不应使用此方法,即,当方法调用的目的是测试零) 的返回值时 (。 若要确定两个字符串是否相等,请调用 Equals 方法。

可以通过参数进一步指定比较,该 options 参数由一个或多个枚举成员组成 CompareOptions 。 但是,由于此方法的目的是执行区分区域性的字符串比较, CompareOptions.Ordinal 因此和 CompareOptions.OrdinalIgnoreCase 值不起作用。

两者或两个比较字都可以 null 。 按照定义,任何字符串(包括 String.Empty 、)比较大于 null 引用,而两个 null 引用的比较结果相等。

当发现不相等或已比较两个字符串时,将终止比较。 但是,如果两个字符串的比较结果与一个字符串的末尾相等,而另一个字符串还剩个字符,则将剩余字符视为更大的字符串。

调用方说明

字符集包括可忽略字符,在执行语言性的或区分区域性的比较时该字符不被考虑。 Compare(String, String, CultureInfo, CompareOptions)当方法执行区分区域性的比较时,它不会考虑此类字符。 若要在比较中识别可忽略字符,请 Ordinal 为参数提供值或 OrdinalIgnoreCase options

另请参阅

适用于