[asp.net] How to encode the plus (+) symbol in a URL

The URL link below will open a new Google mail window. The problem I have is that Google replaces all the plus (+) signs in the email body with blank space. It looks like it only happens with the + sign. How can I remedy this? (I am working on a ASP.NET web page.)

https://mail.google.com/mail?view=cm&tf=0&[email protected]&su=some subject&body=Hi there+Hello there

(In the body email, "Hi there+Hello there" will show up as "Hi there Hello there")

It's safer to always percent-encode all characters except those defined as "unreserved" in RFC-3986.

unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"

So, percent-encode the plus character and other special characters.

The problem that you are having with pluses is because, according to RFC-1866 (HTML 2.0 specification), paragraph 8.2.1. subparagraph 1., "The form field names and values are escaped: space characters are replaced by `+', and then reserved characters are escaped"). This way of encoding form data is also given in later HTML specifications, look for relevant paragraphs about application/x-www-form-urlencoded.

In order to encode + value using JavaScript, you can use encodeURIComponent function.

Example:

var url = "+11";
var encoded_url = encodeURIComponent(url);
console.log(encoded_url)

Just to add this to the list:

Uri.EscapeUriString("Hi there+Hello there") // Hi%20there+Hello%20there
Uri.EscapeDataString("Hi there+Hello there") // Hi%20there%2BHello%20there

See https://stackoverflow.com/a/34189188/98491

Usually you want to use EscapeDataString which does it right.

Is you want a plus (+) symbol in the body you have to encode it as 2B.

For example: Try this