URLEncode / Decode

System.Net.WebUtility class:

Methods

HtmlDecode(String)	Converts a string that has been HTML-encoded for HTTP transmission into a decoded string.
HtmlDecode(String, TextWriter)	Converts a string that has been HTML-encoded into a decoded string, and sends the decoded string to a TextWriter output stream.
HtmlEncode(String)	Converts a string to an HTML-encoded string.
HtmlEncode(String, TextWriter)	Converts a string into an HTML-encoded string, and returns the output as a TextWriter stream of output.
UrlDecode(String)	Converts a string that has been encoded for transmission in a URL into a decoded string.
UrlDecodeToBytes(Byte[], Int32, Int32)	Converts an encoded byte array that has been encoded for transmission in a URL into a decoded byte array.
UrlEncode(String)	Converts a text string into a URL-encoded string.
UrlEncodeToBytes(Byte[], Int32, Int32)	Converts a byte array into a URL-encoded byte array.

using System.Net;
var input = "Some string = /something else?";
var urlEncoded = WebUtility.UrlEncode(input);
// output is Some+string+%3D+%2Fsomething+else%3F