Question

It blew my mind when I found that Uri tostring breaks uris…. Here is an example

If you run this in immediate mode you’d get

new Uri("http://site.com?a=1&b=c%26d").AbsoluteUri

Res

"http://site.com/?a=1&b=c%26d"

But

new Uri("http://site.com?a=1&b=c%26d").ToString() //string.format i believe doesn't need .ToString()

Gets me

"http://site.com/?a=1&b=c&d"

The b value is completely broken. I was shocked. Am I never to use ToString()? This seems like a bug. But writing this question gave me the answer (.AbsoluteUri). But maybe this will help someone.

Answer 1

The Uri.ToString method isn’t useful for anything other than to display the URI in a human friendly way.

From the code example on the documentation for Uri.ToString:

// The following outputs "http://www.contoso.com/thick and thin.htm".
Console.WriteLine(uriAddress.ToString());

// The following outputs "HTTP://www.Contoso.com:80/thick%20and%20thin.htm".
Console.WriteLine(uriAddress.OriginalString);

The example shows that the ToString method returns a string with spaces, which is not a character that is valid in an URI. The string representation of the Uri is clearly not intended to be used as an actual URI. This fact should perhaps be made more clearly in the documentation.