MediaManager throwing null error

Question

I am facing an issue while fetching the media item URL. This is my code snippet:

@{
    Sitecore.Data.Fields.ImageField imageItem = (Sitecore.Data.Fields.ImageField)Sitecore.Context.Item.Fields["BackgroundImage"];

            var titleUrl = Sitecore.Resources.Media.HashingUtils.ProtectAssetUrl(
                               Sitecore.Resources.Media.MediaManager.GetMediaUrl(
                                   imageItem.MediaItem,
                                   new MediaUrlOptions()
                                   {
                                       Language = Sitecore.Context.Language,
                                       Height = 600
                                   }));
}

I am using this titleUrl in the image tag:

<img src="@titleUrl" />

But while fetching the URL, MediaManager is throwing this error:

System.ArgumentNullException
  HResult=0x80004003
  Message=Value cannot be null.
Arg_ParamName_Name
  Source=Sitecore.Kernel
  StackTrace:
   at Sitecore.Diagnostics.Assert.ArgumentNotNull(Object argument, String argumentName)
   at Sitecore.Resources.Media.MediaProvider.GetMediaUrl(MediaItem item, MediaUrlOptions options)
   at ASP._Page_Views_DeepContent_PageHeader_Index_cshtml.Execute() in c:\inetpub\wwwroot\sitecoretac\Views\Index.cshtml:line 13
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
   at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)

What is the issue here? Thanks for the help.

Answer 1

From what I can tell your exception says in fact that you passed null MediaItem to GetMediaUrl method.

It looks like you have a field ImageField imageItem but imageItem.MediaItem is null. It's either not selected or the media item is not published.

Add extra check to your code to render a url only when imageItem.MediaItem is not null:

var titleUrl = imageItem.MediaItem == null
    ? null
    : Sitecore.Resources.Media.HashingUtils.ProtectAssetUrl(
    Sitecore.Resources.Media.MediaManager.GetMediaUrl(
        imageItem.MediaItem,
        new MediaUrlOptions()
        {
            Language = Sitecore.Context.Language,
            Height = 600
        }));

And in your view render <img> tag only when @titleUrl is not null.