How do you UrlEncode without using System.Web?

Question

I am trying to write a windows client application that calls a web site for data. To keep the install to a minimum I am trying only use dlls in the .NET Framework Client Profile. Trouble is that I need to UrlEncode some parameters, is there an easy way to do this without importing System.Web.dll which is not part of the Client Pofile?

Answer 1

The answers here are very good, but still insufficient for me.

I wrote a small loop that compares Uri.EscapeUriString with Uri.EscapeDataString for all characters from 0 to 255.

NOTE: Both functions have the built-in intelligence that characters above 0x80 are first UTF-8 encoded and then percent encoded.

Here is the result:

******* Different *******

'#' -> Uri "#" Data "%23"
'$' -> Uri "$" Data "%24"
'&' -> Uri "&" Data "%26"
'+' -> Uri "+" Data "%2B"
',' -> Uri "," Data "%2C"
'/' -> Uri "/" Data "%2F"
':' -> Uri ":" Data "%3A"
';' -> Uri ";" Data "%3B"
'=' -> Uri "=" Data "%3D"
'?' -> Uri "?" Data "%3F"
'@' -> Uri "@" Data "%40"


******* Not escaped *******

'!' -> Uri "!" Data "!"
''' -> Uri "'" Data "'"
'(' -> Uri "(" Data "("
')' -> Uri ")" Data ")"
'*' -> Uri "*" Data "*"
'-' -> Uri "-" Data "-"
'.' -> Uri "." Data "."
'_' -> Uri "_" Data "_"
'~' -> Uri "~" Data "~"

'0' -> Uri "0" Data "0"
.....
'9' -> Uri "9" Data "9"

'A' -> Uri "A" Data "A"
......
'Z' -> Uri "Z" Data "Z"

'a' -> Uri "a" Data "a"
.....
'z' -> Uri "z" Data "z"

******* UTF 8 *******

.....
'Ò' -> Uri "%C3%92" Data "%C3%92"
'Ó' -> Uri "%C3%93" Data "%C3%93"
'Ô' -> Uri "%C3%94" Data "%C3%94"
'Õ' -> Uri "%C3%95" Data "%C3%95"
'Ö' -> Uri "%C3%96" Data "%C3%96"
.....

EscapeUriString is to be used to encode URLs, while EscapeDataString is to be used to encode for example the content of a Cookie, because Cookie data must not contain the reserved characters '=' and ';'.

Answer 2

To UrlEncode without using System.Web:

String s = System.Net.WebUtility.UrlEncode(str);
//fix some different between WebUtility.UrlEncode and HttpUtility.UrlEncode
s = Regex.Replace(s, "(%[0-9A-F]{2})", c => c.Value.ToLowerInvariant());

more details: https://www.samnoble.co.uk/2014/05/21/beware-webutility-urlencode-vs-httputility-urlencode/