.NET - Get protocol, host, and port

问题

Is there a simple way in .NET to quickly get the current protocol, host, and port? For example, if I\'m on the following URL:

http://www.mywebsite.com:80/pages/page1.aspx

I need to return:

http://www.mywebsite.com:80

I know I can use Request.Url.AbsoluteUri to get the complete URL, and I know I can use Request.Url.Authority to get the host and port, but I\'m not sure of the best way to get the protocol without parsing out the URL string.

Any suggestions?

回答1:

The following (C#) code should do the trick

Uri uri = new Uri("http://www.mywebsite.com:80/pages/page1.aspx");
string requested = uri.Scheme + Uri.SchemeDelimiter + uri.Host + ":" + uri.Port;

回答2:

Even though @Rick has the accepted answer for this question, there's actually a shorter way to do this, using the poorly named Uri.GetLeftPart() method.

Uri url = new Uri("http://www.mywebsite.com:80/pages/page1.aspx");
string output = url.GetLeftPart(UriPartial.Authority);

There is one catch to GetLeftPart(), however. If the port is the default port for the scheme, it will strip it out. Since port 80 is the default port for http, the output of GetLeftPart() in my example above will be http://www.mywebsite.com.

If the port number had been something other than 80, it would be included in the result.

回答3:

Well if you are doing this in Asp.Net or have access to HttpContext.Current.Request I'd say these are easier and more general ways of getting them:

var scheme = Request.Url.Scheme; // will get http, https, etc.
var host = Request.Url.Host; // will get www.mywebsite.com
var port = Request.Url.Port; // will get the port
var path = Request.Url.AbsolutePath; // should get the /pages/page1.aspx part, can't remember if it only get pages/page1.aspx

I hope this helps. :)

回答4:

A more structured way to get this is to use UriBuilder. This avoids direct string manipulation.

var builder = new UriBuilder(Request.Url.Scheme, Request.Url.Host, Request.Url.Port);

回答5:

Request.Url will return you the Uri of the request. Once you have that, you can retrieve pretty much anything you want. To get the protocol, call the Scheme property.

Sample:

Uri url = Request.Url;
string protocol = url.Scheme;

Hope this helps.

回答6:

Even shorter way, may require newer ASP.Net:

string authority = Request.Url.GetComponents(UriComponents.SchemeAndServer,UriFormat.Unescaped)

The UriComponents enum lets you specify which component(s) of the URI you want to include.

回答7:

Very similar to Holger's answer. If you need to grab the URL can do something like:

Uri uri = Context.Request.Url;         
var scheme = uri.Scheme // returns http, https
var scheme2 = uri.Scheme + Uri.SchemeDelimiter; // returns http://, https://
var host = uri.Host; // return www.mywebsite.com
var port = uri.Port; // returns port number

The Uri class provides a whole range of methods, many which I have not listed.

In my instance, I needed to grab LocalHost along with the Port Number, so this is what I did:

var Uri uri = Context.Request.Url;
var host = uri.Scheme + Uri.SchemeDelimiter + uri.Host + ":" + uri.Port;

Which successfully grabbed: http://localhost:12345

来源：https://stackoverflow.com/questions/21640/net-get-protocol-host-and-port

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