StringInfo.GetTextElementEnumerator 方法

参考

定义

命名空间:: System.Globalization

程序集:: System.Globalization.dll

程序集:: System.Runtime.dll

程序集:: netstandard.dll

程序集:: mscorlib.dll

重要

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返回一个循环访问字符串的文本元素的枚举器。

重载

GetTextElementEnumerator(String)	返回一个循环访问整个字符串的文本元素的枚举数。
GetTextElementEnumerator(String, Int32)	返回一个枚举数，它循环访问字符串的文本元素并从指定索引处开始。

GetTextElementEnumerator(String)

返回一个循环访问整个字符串的文本元素的枚举数。

public:
 static System::Globalization::TextElementEnumerator ^ GetTextElementEnumerator(System::String ^ str);

public static System.Globalization.TextElementEnumerator GetTextElementEnumerator (string str);

static member GetTextElementEnumerator : string -> System.Globalization.TextElementEnumerator

Public Shared Function GetTextElementEnumerator (str As String) As TextElementEnumerator

参数

str: String

要循环访问的字符串。

TextElementEnumerator

整个字符串的 TextElementEnumerator。

例外

ArgumentNullException

str 为 null。

示例

下面的示例演示如何调用 GetTextElementEnumerator 方法。此示例是为类提供的更大示例的一部分 StringInfo 。

using namespace System;
using namespace System::Text;
using namespace System::Globalization;


// Show how to enumerate each real character (honoring surrogates)
// in a string.

void EnumTextElements(String^ combiningChars)
{
    // This StringBuilder holds the output results.
    StringBuilder^ sb = gcnew StringBuilder();

    // Use the enumerator returned from GetTextElementEnumerator
    // method to examine each real character.
    TextElementEnumerator^ charEnum =
        StringInfo::GetTextElementEnumerator(combiningChars);
    while (charEnum->MoveNext())
    {
        sb->AppendFormat("Character at index {0} is '{1}'{2}", 
            charEnum->ElementIndex, charEnum->GetTextElement(), 
            Environment::NewLine);
    }

    // Show the results.
    Console::WriteLine("Result of GetTextElementEnumerator:");
    Console::WriteLine(sb);
}


// Show how to discover the index of each real character
// (honoring surrogates) in a string.

void EnumTextElementIndexes(String^ combiningChars)
{
    // This StringBuilder holds the output results.
    StringBuilder^ sb = gcnew StringBuilder();

    // Use the ParseCombiningCharacters method to
    // get the index of each real character in the string.
    array <int>^ textElemIndex =
        StringInfo::ParseCombiningCharacters(combiningChars);

    // Iterate through each real character showing the character
    // and the index where it was found.
    for (int i = 0; i < textElemIndex->Length; i++)
    {
        sb->AppendFormat("Character {0} starts at index {1}{2}",
            i, textElemIndex[i], Environment::NewLine);
    }

    // Show the results.
    Console::WriteLine("Result of ParseCombiningCharacters:");
    Console::WriteLine(sb);
}

int main()
{

    // The string below contains combining characters.
    String^ combiningChars = L"a\u0304\u0308bc\u0327";

    // Show each 'character' in the string.
    EnumTextElements(combiningChars);

    // Show the index in the string where each 'character' starts.
    EnumTextElementIndexes(combiningChars);

};

// This code produces the following output.
//
// Result of GetTextElementEnumerator:
// Character at index 0 is 'a-"'
// Character at index 3 is 'b'
// Character at index 4 is 'c,'
//
// Result of ParseCombiningCharacters:
// Character 0 starts at index 0
// Character 1 starts at index 3
// Character 2 starts at index 4

using System;
using System.Text;
using System.Globalization;

public sealed class App {
   static void Main() {
      // The string below contains combining characters.
      String s = "a\u0304\u0308bc\u0327";

      // Show each 'character' in the string.
      EnumTextElements(s);

      // Show the index in the string where each 'character' starts.
      EnumTextElementIndexes(s);
   }

   // Show how to enumerate each real character (honoring surrogates) in a string.
   static void EnumTextElements(String s) {
      // This StringBuilder holds the output results.
      StringBuilder sb = new StringBuilder();

      // Use the enumerator returned from GetTextElementEnumerator
      // method to examine each real character.
      TextElementEnumerator charEnum = StringInfo.GetTextElementEnumerator(s);
      while (charEnum.MoveNext()) {
         sb.AppendFormat(
           "Character at index {0} is '{1}'{2}",
           charEnum.ElementIndex, charEnum.GetTextElement(),
           Environment.NewLine);
      }

      // Show the results.
      Console.WriteLine("Result of GetTextElementEnumerator:");
      Console.WriteLine(sb);
   }

   // Show how to discover the index of each real character (honoring surrogates) in a string.
   static void EnumTextElementIndexes(String s) {
      // This StringBuilder holds the output results.
      StringBuilder sb = new StringBuilder();

      // Use the ParseCombiningCharacters method to
      // get the index of each real character in the string.
      Int32[] textElemIndex = StringInfo.ParseCombiningCharacters(s);

      // Iterate through each real character showing the character and the index where it was found.
      for (Int32 i = 0; i < textElemIndex.Length; i++) {
         sb.AppendFormat(
            "Character {0} starts at index {1}{2}",
            i, textElemIndex[i], Environment.NewLine);
      }

      // Show the results.
      Console.WriteLine("Result of ParseCombiningCharacters:");
      Console.WriteLine(sb);
   }
}

// This code produces the following output:
//
// Result of GetTextElementEnumerator:
// Character at index 0 is 'ā̈'
// Character at index 3 is 'b'
// Character at index 4 is 'ç'
//
// Result of ParseCombiningCharacters:
// Character 0 starts at index 0
// Character 1 starts at index 3
// Character 2 starts at index 4

Imports System.Text
Imports System.Globalization

Public Module Example
   Public Sub Main()
      ' The string below contains combining characters.
      Dim s As String = "a" + ChrW(&h0304) + ChrW(&h0308) + "bc" + ChrW(&h0327)

      ' Show each 'character' in the string.
      EnumTextElements(s)

      ' Show the index in the string where each 'character' starts.
      EnumTextElementIndexes(s)
   End Sub

   ' Show how to enumerate each real character (honoring surrogates) in a string.
   Sub EnumTextElements(s As String)
      ' This StringBuilder holds the output results.
      Dim sb As New StringBuilder()

      ' Use the enumerator returned from GetTextElementEnumerator 
      ' method to examine each real character.
      Dim charEnum As TextElementEnumerator = StringInfo.GetTextElementEnumerator(s)
      Do While charEnum.MoveNext()
         sb.AppendFormat("Character at index {0} is '{1}'{2}",
                         charEnum.ElementIndex, 
                         charEnum.GetTextElement(),
                         Environment.NewLine)
      Loop

      ' Show the results.
      Console.WriteLine("Result of GetTextElementEnumerator:")
      Console.WriteLine(sb)
   End Sub

   ' Show how to discover the index of each real character (honoring surrogates) in a string.
   Sub EnumTextElementIndexes(s As String)
      ' This StringBuilder holds the output results.
      Dim sb As New StringBuilder()

      ' Use the ParseCombiningCharacters method to 
      ' get the index of each real character in the string.
      Dim textElemIndex() As Integer = StringInfo.ParseCombiningCharacters(s)

      ' Iterate through each real character showing the character and the index where it was found.
      For i As Int32 = 0 To textElemIndex.Length - 1
         sb.AppendFormat("Character {0} starts at index {1}{2}",
                         i, textElemIndex(i), Environment.NewLine)
      Next

      ' Show the results.
      Console.WriteLine("Result of ParseCombiningCharacters:")
      Console.WriteLine(sb)
   End Sub
End Module
' The example displays the following output:
'
'       Result of GetTextElementEnumerator:
'       Character at index 0 is 'ā̈'
'       Character at index 3 is 'b'
'       Character at index 4 is 'ç'
'       
'       Result of ParseCombiningCharacters:
'       Character 0 starts at index 0
'       Character 1 starts at index 3
'       Character 2 starts at index 4

注解

.NET 将文本元素定义为显示为单个字符（即字形）的文本单元。文本元素可以是基字符、代理项对或组合字符序列。 Unicode 标准将代理项对定义为单个抽象字符的编码字符表示形式，该字符由两个代码单元组成，其中，对的第一个单元为高代理项，第二个是低代理项。 Unicode 标准将组合字符序列定义为基字符和一个或多个组合字符的组合。代理项对可表示基字符或组合字符。

文本元素枚举器仅用于读取字符串中的数据;它不能修改基础字符串。枚举器没有对字符串的独占访问权限。

如果枚举器位于字符串中第一个文本元素之前或字符串中的最后一个文本元素之后，则该枚举器处于无效状态。如果枚举器处于无效状态，则调用会 Current 引发异常。

最初，枚举器位于字符串中第一个文本元素之前。 Reset 也会将枚举器放回此位置。因此，在创建枚举器或调用之后 Reset ， MoveNext 必须先调用，以将枚举数前移到字符串的第一个文本元素，然后才能读取的值 Current 。

在调用 Current 或 MoveNext 之前，Reset 返回同一对象。

传递字符串末尾后，枚举器将再次处于无效状态并调用 MoveNext 返回 false 。 Current如果最后一次调用返回，则调用会引发异常 MoveNext false 。

另请参阅

TextElementEnumerator

适用于

GetTextElementEnumerator(String, Int32)

返回一个枚举数，它循环访问字符串的文本元素并从指定索引处开始。

public:
 static System::Globalization::TextElementEnumerator ^ GetTextElementEnumerator(System::String ^ str, int index);

public static System.Globalization.TextElementEnumerator GetTextElementEnumerator (string str, int index);

static member GetTextElementEnumerator : string * int -> System.Globalization.TextElementEnumerator

Public Shared Function GetTextElementEnumerator (str As String, index As Integer) As TextElementEnumerator

参数

str: String

要循环访问的字符串。

index: Int32

开始迭代处的从零开始的索引。

TextElementEnumerator

在 index 处开始的字符串的 TextElementEnumerator。

例外

ArgumentNullException

str 为 null。

ArgumentOutOfRangeException

index 超出了 str 的有效索引范围。

注解

文本元素枚举器仅用于读取字符串中的数据;它不能修改基础字符串。枚举器没有对字符串的独占访问权限。

在调用 Current 或 MoveNext 之前，Reset 返回同一对象。

传递字符串末尾后，枚举器将再次处于无效状态并调用 MoveNext 返回 false 。 Current如果最后一次调用返回，则调用会引发异常 MoveNext false 。

另请参阅

TextElementEnumerator

适用于

StringInfo.GetTextElementEnumerator 方法

定义

重载

GetTextElementEnumerator(String)

参数

返回

例外

示例

注解

另请参阅

适用于

GetTextElementEnumerator(String, Int32)

参数

返回

例外

注解

另请参阅

适用于

其他资源