Category: .NET Core

ImageTagHelper in .NET Core–add data URI scheme

The ImageTagHelper in ASP.NET Core MVC ( is lacking one attribute that I find somehow useful: a data uri to embed the image as base64 ( )

I was curious about how fast it will be to make such a modification on my PC.

So the process was:

  1. Downloading branch rel/1.1.1 from as a zip file
  2. Unlock the file, unpack, run  MVC.sln with VS2015
  3. Compile the entire project.
  4. See tests  ( also run dotnet test in the Mvc-rel-1.1.1\test\Microsoft.AspNetCore.Mvc.TagHelpers.Test to figure what was missing)
  5. Started modifying the file ImageTagHelper( adding
     public bool RenderBase64 

    and creating FileBase64ContentProvider.cs with the (approximately) same content as FileVersionProvider

  6. Adding tests to  mvc-rel-1.1.1\test\microsoft.aspnetcore.mvc.taghelpers.test\imagetaghelpertest.cs  ( also modifying mocker –
    for my purposes, to read the file, I need file length

                    .Setup(m => m.CreateReadStream())                
                    .Returns(() => new MemoryStream(Encoding.UTF8.GetBytes("Hello World!")));
    mockFile.SetupGet(f => f.Length).Returns(12);
  7. Modifying HtmlTargetElement attribute from ImageTagHelper
  8. Adding “Microsoft.AspNetCore.StaticFiles”: “1.1.0”, and app.UseStaticFiles();  to HtmlGenerationWebSite and going to http://localhost:5551/HtmlGeneration_Home/image

And that was all. Now I will see how to fork and submit changes 😉

Later Edit: Submit a bug, fork, pull request. Approved.

ASP.NET Core and Windows Authentication

Just a reminder of how to configure ASP.NET Core and Windows Authentication

1. Configure IIS

2. Go to properties folder, file launchSettings.json and modify

"iisSettings": {     "windowsAuthentication": true,     "anonymousAuthentication": false,    //other data

3. When you compile and run , the Web.Config will be modified for forwardWindowsAuthToken :

<aspNetCore processPath="%LAUNCHER_PATH%" arguments="%LAUNCHER_ARGS%" forwardWindowsAuthToken="true" stdoutLogEnabled="false" />