Blog: Inline images from the media library.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Sitecore.Web.UI.WebControls;
using System.Web.UI;
using System.Net;
using Sitecore.Data.Fields;

namespace InlineImageRenderer
{
    /// <summary>
    /// Convert a Sitecore image to an inline image.
    /// </summary>
    public class InlineImage : Image
    {
        protected override void Render(HtmlTextWriter output)
        {
            // use normal rendering so that you can get the URL
            string img = RenderAsText();

            // parse the URL from the image tag
            int srcIndex = ! string.IsNullOrEmpty(img) && img.IndexOf("src=\"") > 0 ? img.IndexOf("src=\"") + 5 : -1;
            if (srcIndex > 0)
            {
                string imgUrl = img.Substring(srcIndex, img.IndexOf('\"', srcIndex) - srcIndex);
                string absoluteUri = System.Web.HttpContext.Current.Request.Url.AbsoluteUri;
                string fullImgUrl = string.Format("{0}/{1}", absoluteUri.Substring(0, absoluteUri.IndexOf('/', absoluteUri.IndexOf("//") + 2)), imgUrl);

                // download the image using WebClient
                WebClient client = new WebClient();
                byte[] imgData = client.DownloadData(fullImgUrl);
                if (imgData != null && imgData.Length > 0)
                {
                    // find the mime type as set on the item in the media library
                    ImageField imageField = FieldTypeManager.GetField(this.GetItem().Fields[Field]) as ImageField;
                    if (imageField != null)
                    {
                        // write the image tag and replace the URL with the inline image data
                        output.Write(img.Substring(0, srcIndex));
                        output.Write(string.Format("data:{0};base64,{1}", imageField.MediaItem.Fields["Mime Type"].Value, Convert.ToBase64String(imgData)));
                        output.Write(img.Substring(srcIndex + imgUrl.Length));
                    }
                }
            }
        }
    }
}