content type by extension

Question

Is there any built in function that returns the content type based on the file extension?

Answer 1

Not that I know of. But you can use this code:

using Microsoft.Win32;

RegistryKey key = Registry.ClassesRoot.OpenSubKey(extension);
string contentType = key.GetValue("Content Type").ToString();

You'll need to add extra code for error handling.

Note: The extension needs to be prefixed by a dot, like in .txt.

Answer 2

Since .Net Framework 4.5 there is a class System.Web.MimeMapping which has a complete library of mime types with methods to get the requested mime type.

See: http://msdn.microsoft.com/en-us/library/system.web.mimemapping(v=vs.110).aspx

or for the implementation of GetMimeMapping: https://referencesource.microsoft.com/#System.Web/MimeMapping.cs