Question

In my view I use the following code to get an image from my database (through an action method) and display it in a html tag

<img src="@Url.Action("DownloadBackground", new { projectID = 31 })" />

The Action method named DownloadBackground return a FileContentResult with the image stored in my DB. It works but I would like to create a helper method to replace it.

I would like something like:

@Html.BackgroundFor(31) 

Where 31 is the id of the project I need. I would like this helper method to produce the same html code.

So I try to create my helper like this:

public static MvcHtmlString BackgroundFor(this HtmlHelper helper, int id)
{
    // What code here ?? 

    var builder = new TagBuilder("a");
    builder.MergeAttribute("src", ???);
    return new MvcHtmlString(builder.ToString(TagRenderMode.SelfClosing));
}

Answer 1

Try this:

builder.MergeAttribute("src", new UrlHelper(helper.ViewContext.RequestContext)
                                    .Action("DownloadBackground",
                                            new { projectID = id }));

or, you can use

new UrlHelper(((MvcHandler)HttpContext.Current.Handler).RequestContext)

This would do too