HttpEncoder.HtmlEncode(String, TextWriter) Method

Definition

Namespace:

System.Web.Util

Assemblies:

System.Web.dll, System.Web.Services.dll

Encodes a string into an HTML-encoded string.

protected public:
 virtual void HtmlEncode(System::String ^ value, System::IO::TextWriter ^ output);

protected internal virtual void HtmlEncode (string value, System.IO.TextWriter output);

abstract member HtmlEncode : string * System.IO.TextWriter -> unit
override this.HtmlEncode : string * System.IO.TextWriter -> unit

Protected Friend Overridable Sub HtmlEncode (value As String, output As TextWriter)

Parameters

value

String

The string to encode.

output

TextWriter

The text writer to write the encoded value to.

Exceptions

ArgumentNullException

output is null.

Remarks

The following table lists the character sequences that the ASP.NET encoding logic can decode.

Character	Encoded as
< (left angle bracket)	&lt;
> (right angle bracket)	&gt;
" (double quotation marks)	&quot;
& (ampersand)	&amp;
\ (backslash)	&#92;
ASCII characters from 160 to 255	&#NNN;, where NNN is the three-digit decimal character code

If you override the HtmlEncode method, you must produce output that is also safe within double-quoted or single-quoted HTML attributes. This accommodates parsing by the Razor engine, where markup and code can be combined, such as <tag attr="@value">. In addition, the @ operator is not context-aware when processed by the Razor engine, therefore it calls HtmlEncode rather than HtmlAttributeEncode.