This is a complete implementation of the Gravatar image request API, according the Gravatar documentation, as an ASP.Net MVC HtmlHelper.

• Size
• Default image (404, mystery-man, identicon, monsterid, wavatar, retro)
• Custom default image (url)
• Force default image
• Ratings
• Secure requests (HTTPS) is automatic (but can be forced)
• Named and Optional Arguments for .Net 4.0 and above
• Custom CSS class attribute string (cssClass)
• Custom alt attribute string alt)

1. Drop the GravatarHtmlHelper_{version}.cs file anywhere in your ASP.Net MVC project:

   GravatarHtmlHelper_NetCore.cs 🆕
   for .Net Core / ASP.Net Core MVC

   GravatarHtmlHelper_Net40.cs
   for .Net 4.0+ / ASP.Net MVC 3, 4, 5+

   GravatarHtmlHelper_Net35.cs
   for .Net 3.5 / ASP.Net MVC 2.0

2. Recompile and start using it in your Views:

@Html.GravatarImage("user.name@email.com")

@Html.GravatarImage(
 "user.name@email.com",
 size: 32,
 defaultImage: GravatarHtmlHelper.DefaultImage.Identicon,
 rating: GravatarHtmlHelper.Rating.PG,
 cssClass: "gravatar img-responsive")

That's it. No attribution required, but feel free to leave a comment on my blog if you find it useful

Mark Mailer has a TagHelper implementation for ASP.Net Core MVC