public static string ResizeBackground(this HtmlHelper helper, ContentReference image,
BackgroundPictureProfile profile)
{
if (image == null)
{
return("error-no-image");
}
var className = "_" + Guid.NewGuid().ToString("N");
var styles = GenerateMediaQueryStyles(helper, profile, image, className);
helper.RenderXhtmlString(new XhtmlString(styles));
return(className);
}
private static string GenerateMediaQueryStyles(HtmlHelper helper, BackgroundPictureProfile profile,
ContentReference image, string className)
{
var stringBuilder = new StringBuilder();
stringBuilder.Append("<style>");
foreach (var allowedSize in profile.AllowedSizes.Reverse())
{
var mediaQuery = helper.Encode(allowedSize.MediaCondition);
RenderNonRetinaCss(helper, image, mediaQuery, stringBuilder, className, allowedSize, profile.Format);
RenderRetinaCss(helper, image, mediaQuery, stringBuilder, className, allowedSize, profile.Format);
}
stringBuilder.Append("</style>");
return(stringBuilder.ToString());
}
