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StringInfo.ParseCombiningCharacters Method

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

[Visual Basic]
Public Shared Function ParseCombiningCharacters( _
   ByVal str As String _
) As Integer()
public static int[] ParseCombiningCharacters(
 string str
public: static int ParseCombiningCharacters(
 String* str
)  __gc[];
public static function ParseCombiningCharacters(
   str : String
) : int[];


The string to search.

Return Value

An array of integers that contains the zero-based indexes of each base character, high-surrogate, or control character within the specified string.


Exception Type Condition
ArgumentNullException str is a null reference (Nothing in Visual Basic).


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 whose 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. For more information on surrogate pairs and combining character sequences, see The Unicode Standard at

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 would return the indexes 0, 2, and 4.


Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

See Also

StringInfo Class | StringInfo Members | System.Globalization Namespace

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