MVC5如何在代码中找到根路径？

Question

I have some helper methods to build Html output but it only comes out correct on my local dev and not my staging server. The ~ doesn't work since this is not Razor.

My local site path is http://localhost/testSite
My staging path is http://192.168.1.2/

On my local this produces src="/testSite/images.test.jpg"
On my staging instance it produces src="//images.test.jpg"

var baseUrl = HttpRuntime.AppDomainAppPath;
var tb = new TagBuilder("img");
tb.MergeAttribute("title", "Main Image");
tb.MergeAttribute("src", baseUrl +"\images\test.jpg");
return new MvcHtmlString(tb.ToString(TagRenderMode.SelfClosing));

I'm sure there is a method built in to do this on the code side

Answer 1

var baseUrl = System.Web.Mvc.UrlHelper.GenerateContentUrl("~/images/", HttpContext.Current);

Using the GenerateContentUrl you can keep using ~/

Answer 2

Ugh... after reviewing all the helpers and context objects available, I must conclude there is no function or method that provides exactly what you want (other than to use the tilde in one of the functions, as shown in the other answers). All of them require some sort of string processing (eg Split() or TrimEnd() ) in order to work.

Instead, Microsoft kindly gave us a band-aid function, AppendTrailingSlash , which you can use to solve the problem like this:

var baseUrl = VirtualPathUtility.AppendTrailingSlash(HttpRuntime.AppDomainAppPath);
var tb = new TagBuilder("img");
tb.MergeAttribute("title", "Main Image");
tb.MergeAttribute("src", baseUrl +"images/test.jpg");  //notice I removed the initial slash
return new MvcHtmlString(tb.ToString(TagRenderMode.SelfClosing));

AppendTrailingSlash is guaranteed not to "double up" on the forward slash when the virtual directory is "/", so this should work for both your staging and development environments.

PS I'm pretty sure you should be using AppDomainAppVirtualPath and not AppDomainAppPath , which provides the physical path and not the virtual one.

Answer 3

Hi you can try also with Using double dot notation in URL link

ex:

../file would mean to look in the parent directory for file. If you had just file it would look in the current directory.

Thanks