The tp://go.microsoft.com/fwlink/?linkid=37123 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 tp://go.microsoft.com/fwlink/?linkid=37123 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 erload:System.Globalization.StringInfo.SubstringByTextElements method and StringInfo.LengthInTextElements property provide an easy to use implementation of the functionality offered by the StringInfo.ParseCombiningCharacters(string) method.

Namespace: System.Globalization
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0