What's the difference between Uri.ToString() and Uri.AbsoluteUri?

Question

As a comment to an Azure question just now, @smarx noted

I think it's generally better to do blob.Uri.AbsoluteUri than blob.Uri.ToString().

Is there a reason for this? The documentation for Uri.AbsoluteUri notes that it "Gets the absolute URI", Uri.ToString() "Gets a canonical string representation for the specified instance."

Answer 1

Given for example:

UriBuilder builder = new UriBuilder("http://somehost/somepath");
builder.Query = "somekey=" + HttpUtility.UrlEncode("some+value");
Uri someUri = builder.Uri;

In this case, Uri.ToString() will return a human-readable URL: http://somehost/somepath?somekey=some+value

Uri.AbsoluteUri on the other hand will return the encoded form as HttpUtility.UrlEncode returned it: http://somehost/somepath?somekey=some%2bvalue

Answer 2

Additionally: If your Uri is a relative Uri AbsoluteUri will fail, ToString() not.

Uri uri = new Uri("fuu/bar.xyz", UriKind.Relative);
string str1 = uri.ToString(); // "fuu/bar.xyz"
string str2 = uri.AbsoluteUri; // InvalidOperationException

Answer 3

为什么不检查并使用正确的呢？

string GetUrl(Uri uri) => uri?.IsAbsoluteUri == true ? uri?.AbsoluteUri : uri?.ToString();

Answer 4

Since everybody seems to think that uri.AbsoluteUri is better, but because it fails with relative paths, then probably the universal way would be:

Uri uri = new Uri("fuu/bar.xyz", UriKind.Relative);
string notCorruptUri = Uri.EscapeUriString(uri.ToString());

Answer 5

The following example writes the complete contents of the Uri instance to the console. In the example shown,

http://www.cartechnewz.com/catalog/shownew.htm?date=today

is written to the console.

Uri baseUri = new Uri("http://www.cartechnewz.com");
Uri myUri = new Uri(baseUri, "catalog/shownew.htm?date=today");
Console.WriteLine(myUri.AbsoluteUri);

The AbsoluteUri property includes the entire URI stored in the Uri instance, including all fragments and query strings.