XmlWriter.WriteSurrogateCharEntity(Char, Char) Method


When overridden in a derived class, generates and writes the surrogate character entity for the surrogate character pair.

 abstract void WriteSurrogateCharEntity(char lowChar, char highChar);
public abstract void WriteSurrogateCharEntity (char lowChar, char highChar);
abstract member WriteSurrogateCharEntity : char * char -> unit
Public MustOverride Sub WriteSurrogateCharEntity (lowChar As Char, highChar As Char)



The low surrogate. This must be a value between 0xDC00 and 0xDFFF.


The high surrogate. This must be a value between 0xD800 and 0xDBFF.


An invalid surrogate character pair was passed.

An XmlWriter method was called before a previous asynchronous operation finished. In this case, InvalidOperationException is thrown with the message "An asynchronous operation is already in progress."


This method is only applicable on systems that use UTF-16 encoding.

The surrogate character entity is written in hexadecimal format. The range for surrogate characters is #x10000 to #x10FFFF. The following formula is used to generate the surrogate character entity: (highChar -0xD800) * 0x400 + (lowChar -0xDC00) + 0x10000

For both HTML and XML, the document character set (and therefore the notation of numeric character references) is based on UCS [ISO-10646]. A single numeric character reference in a source document may therefore in some cases correspond to two 16-bit units in a string (a high surrogate and a low surrogate). These 16-bit units are referred to as a surrogate pair.

For more information regarding surrogates or characters, refer to section 3.7 of the Unicode 3.0/Unicode 2.0 standard located at https://www.unicode.org, or section 2.2 of the W3C XML 1.0 Recommendation.

For the asynchronous version of this method, see WriteSurrogateCharEntityAsync.

Applies to