GetAscii(System.String,System.Int32,System.Int32)

Encodes the specified number of characters in a substring of domain name labels that include Unicode characters outside the US-ASCII character range. The substring is converted to a string of displayable Unicode characters in the US-ASCII character range and is formatted according to the IDNA standard.

Syntax

public string GetAscii (string unicode, int index, int count)

Parameters

unicode
The string to convert, which consists of one or more domain name labels delimited with label separators.
index
A zero-based offset into unicode that specifies the start of the substring.
count
The number of characters to convert in the substring that starts at the position specified by index in the unicode string.

Returns

The equivalent of the substring specified by the unicode, index, and count parameters, consisting of displayable Unicode characters in the US-ASCII character range (U+0020 to U+007E) and formatted according to the IDNA standard.

Remarks

The Unicode, index, and count parameters define a substring with one or more labels that consist of valid Unicode characters. The labels are separated by label separators. The first character of the substring cannot begin with a label separator, but it can include and optionally end with a separator. The label separators are FULL STOP (period, U+002E), IDEOGRAPHIC FULL STOP (U+3002), FULLWIDTH FULL STOP (U+FF0E), and HALFWIDTH IDEOGRAPHIC FULL STOP (U+FF61). For example, the domain name "www.adatum.com" consists of the labels, "www", "adatum", and "com", separated by periods.

A label cannot contain any of the following characters:

Unicode control characters from U+0001 through U+001F, and U+007F.
Unassigned Unicode characters, depending on the value of the IdnMapping.AllowUnassigned property.
Non-standard characters in the US-ASCII character range, such as the SPACE (U+0020), EXCLAMATION MARK (U+0021), and LOW LINE (U+005F) characters, depending on the value of the IdnMapping.UseStd3AsciiRules property.
Characters that are prohibited by a specific version of the IDNA standard. For more information about prohibited characters, see tp://go.microsoft.com/fwlink/?LinkId=231873 for IDNA 2003, and tp://go.microsoft.com/fwlink/?LinkId=231877 for IDNA 2008.

The erload:System.Globalization.IdnMapping.GetAscii method converts all label separators to FULL STOP (period, U+002E). If the substring contains no characters outside the US-ASCII character range, and no characters within the US-ASCII character range are prohibited, the method returns the substring unchanged.

Requirements

Namespace: System.Globalization
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 2.0.0.0, 4.0.0.0
Since: .NET 2.0