What is the difference between Server.MapPath and HostingEnvironment.MapPath?

Question

Is there any difference between Server.MapPath() and HostingEnvironment.MapPath()? Does Server.MapPath() have any advantages over HostingEnvironment.MapPath()?

My original problem was mapping the file path on a server when the HttpContext is not present and I cannot pass a Server variable from Global.asax to my method.

I used HostingEnvironment.MapPath() instead since it doesn't need HttpContext. Are there any situations when these two methods will give different results?

Kaine

Related post - Server.MapPath("."), Server.MapPath("~"), Server.MapPath(@"\"), Server.MapPath("/"). What is the difference? – Assumpsit

Answer 1

Server.MapPath() eventually calls HostingEnvironment.MapPath(), but it creates a VirtualPath object with specific options:

The VirtualPath object passed to HostingEnvironment.MapPath() is constructed like this:

VirtualPath.Create(path, VirtualPathOptions.AllowAllPath|VirtualPathOptions.AllowNull);

Edit: in reality, the only difference is that you are allowed to pass null to Server.MapPath(), but not to HostingEnvironment.MapPath()

Pogy

So I will always get same results from both methods, right? (excluding null argument) – Kaine

TL;DR: always use HostingEnvironment.MapPath() to keep sanity. (+1) – Limekiln

There must be something different beyond null because Server.MapPath("myFolder") works fine but to get the same result with HostingEnvironment, I had to use HostingEnvironment.MapPath("~/myFolder"). – Griceldagrid

Fantastic answer for initiating an ftp session via a call to a web service. Saved me huge today!!! – Armrest

Actually there is another difference - relative paths (e.g. Image/pict.png) are not allowed with HostingEnvironment.MapPath. – Fomentation

Answer 2

Server.MapPath() requires an HttpContext. HostingEnvironment.MapPath does not.

Brighton

but both require System.Web so will they work with Self Hosted OWIN environments? – Aramen

Answer 3

Are there any situations when these two methods will give different results?

In WCF service, because of the null HttpContext.Current, you can't get the path by Server.MapPath() and will get a HttpException, but you can get the path by HostingEnvironment.MapPath().

// This will get a Http Exception
string path = System.Web.HttpContext.Current.Server.MapPath("myPath");
// This will get your path
string path = System.Web.HostingEnvironment.MapPath("~/myPath");

Reference:

• HttpServerUtility.MapPath(String)
• WCF services and ASP.NET - WCF | Microsoft Docs
• c# - How to MapPath with RequestContext in WCF Service - Stack Overflow

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