Hi froad, 

I created a document type for handling images, I select the image file with media upload and then, just after publishing the document, I create a thumbnail maintaining the image aspect ratio.

1. Implement an event handler in a new class that inherits from ApplicationBase:

public class ApplicationBases : ApplicationBase
{                
  public ApplicationBases()
  {
          //Declare handler
          Document.AfterPublish += new Document.PublishEventHandler(Document_AfterPublish);
  }

2. Write the handler function:

This function will retrieve the image name, load this image and create a new copy with the given dimensions.

  void Document_AfterPublish(Document sender, umbraco.cms.businesslogic.PublishEventArgs e)
  {
     if (sender.ContentType.Alias == "yourdocument")
     {
          if(   sender.getProperty("imagepropertyofdocument").Value != null )
          {
             var dimension = sender.getProperty("thumnailsize").Value 
             resizefile(sender.getProperty("imagepropertyofdocument").Value,dimesion);                         }
          }
     } 
}

The chosen image file is stored in a new media directory with a copy of the image in thumbnail format.

Is this what you are looking for?

HTH.

Sincere regards,
Eduardo Macho

So, then how do I display the thumbnail when I click the media item?  If I take away the Upload file property, then how do I display a thumbnail in the backend?

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