public static MvcHtmlString DataUriImage <T>(this HtmlHelper <T> htmlHelper, string image, IDictionary <string, object> htmlAttributes)
{
DataUriImage dataUriImage = GetDataUriImageFromCache(image, htmlHelper.ViewContext.HttpContext);
var tb = GetTagbuilder(dataUriImage, htmlAttributes);
return(MvcHtmlString.Create(tb.ToString(TagRenderMode.Normal)));
}
private static TagBuilder GetTagbuilder(DataUriImage image, IDictionary <string, object> htmlAttributes)
{
TagBuilder tb = new TagBuilder("span");
tb.MergeAttributes(htmlAttributes);
tb.MergeAttribute("style", string.Format(";width:{0}px;height:{1}px;display:inline-block;", image.Width, image.Height));
tb.MergeAttribute("class", image.Id);
MothScriptHelper.RegisterDataUri(image.Id, image.ImageUrl);
return(tb);
}
internal static DataUriImage GetDataUriImageFromCache(string image, HttpContextBase httpContext)
{
return(Provider.GetFromCache("datauri." + image, () =>
{
var img = new DataUriImage();
img.ImageUrl = image;
byte[] buffer;
Uri uri;
if (Uri.TryCreate(image, UriKind.RelativeOrAbsolute, out uri) && uri.IsAbsoluteUri)
{
// download the file
using (var wc = new WebClient())
{
buffer = wc.DownloadData(uri);
}
}
else
{
buffer = File.ReadAllBytes(httpContext.Server.MapPath("~/" + image.TrimStart('~').TrimStart('/')));
}
using (var imageStream = new MemoryStream(buffer))
{
var bitmap = Image.FromStream(imageStream);
img.Width = bitmap.Width;
img.Height = bitmap.Height;
img.Type = GetStringFromImageType(bitmap.RawFormat);
}
img.Base64 = Convert.ToBase64String(buffer);
img.Id = "";
while (img.Id.Length < 10)
{
img.Id += (char)('a' + Random.Next(26));
}
return img;
}, Provider.CacheDurations.DataUri));
}
