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.NET Framework Class Library
StringInfoParseCombiningCharacters Method

Returns the indexes of each base character, high surrogate, or control character within the specified string.

Namespace:   System.Globalization
Assembly:  mscorlib (in mscorlib.dll)
Syntax
Public Shared Function ParseCombiningCharacters ( _
	str As [%$TOPIC/2wayc3ak_en-us_VS_110_1_0_0_0_0%] _
) As [%$TOPIC/2wayc3ak_en-us_VS_110_1_0_0_0_1%]()
public static [%$TOPIC/2wayc3ak_en-us_VS_110_1_0_1_0_0%][] ParseCombiningCharacters(
	[%$TOPIC/2wayc3ak_en-us_VS_110_1_0_1_0_1%] str
)
public:
static array<[%$TOPIC/2wayc3ak_en-us_VS_110_1_0_2_0_0%]>^ ParseCombiningCharacters(
	[%$TOPIC/2wayc3ak_en-us_VS_110_1_0_2_0_1%]^ str
)
static member ParseCombiningCharacters : 
        str:[%$TOPIC/2wayc3ak_en-us_VS_110_1_0_3_0_0%] -> [%$TOPIC/2wayc3ak_en-us_VS_110_1_0_3_0_1%][] 

Parameters

str
Type: SystemString

The string to search.

Return Value

Type: SystemInt32
An array of integers that contains the zero-based indexes of each base character, high surrogate, or control character within the specified string.
Exceptions
ExceptionCondition
ArgumentNullException

str is .

Remarks

The Unicode Standard defines a surrogate pair as a coded character representation for a single abstract character that consists of a sequence of two code units, where the first unit of the pair is a high surrogate and the second is a low surrogate. A high surrogate is a Unicode code point in the range U+D800 through U+DBFF and a low surrogate is a Unicode code point in the range U+DC00 through U+DFFF.

A control character is a character for which the Unicode value is U+007F or in the range U+0000 through U+001F or U+0080 through U+009F.

The .NET Framework defines a text element as a unit of text that is displayed as a single character, that is, a grapheme. A text element can be a base character, a surrogate pair, or a combining character sequence. The Unicode Standard defines a combining character sequence as a combination of a base character and one or more combining characters. A surrogate pair can represent a base character or a combining character.

If a combining character sequence is invalid, every combining character in that sequence is also returned.

Each index in the resulting array is the beginning of a text element, that is, the index of the base character or the high surrogate.

The length of each element is easily computed as the difference between successive indexes. The length of the array will always be less than or equal to the length of the string. For example, given the string "\u4f00\u302a\ud800\udc00\u4f01", this method returns the indexes 0, 2, and 4.

Equivalent Members

Starting in version 2.0 of the .NET Framework, the SubstringByTextElements method and LengthInTextElements property provide an easy to use implementation of the functionality offered by the ParseCombiningCharacters method.

Examples

The following code example demonstrates calling the ParseCombiningCharacters method. This code example is part of a larger example provided for the StringInfo class.

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 '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 '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 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
Version Information

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1
Platforms

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.