ISO 9075 encoding

XML attribute names can only start with and contain certain characters.
XML属性名称只能以某些字符开头并包含这些字符。

Invalid characters are encoded in the form ‘xhhhh‘ where the four digits represent the hex encoding of the character.
无效字符的编码格式为“xhhhh”，其中四位数字表示字符的十六进制编码。

For example, the space character, ‘a b’, would get encoded to ‘a_x0020_b’. If the initial string contains a pattern that matches ‘xhhhh‘, the first ‘‘ is encoded. For example, ‘axabcd_b’ is encoded as ‘a_x005f_abcd_b’.
例如，空格字符“a b”将被编码为“a_x0020_b”。如果初始字符串包含与“xhhhh”匹配的模式，则对第一个“”进行编码。例如，“axabcd_b”编码为“a_x005f_abcd_b”。

var rawString = "//test:123 DIR/FILE.TXT @";
var encodedString = search.ISO9075Encode(rawString);
var decodedString = search.ISO9075Decode(encodedString);