WebImageHREF is called when server-side script uses the Image.AsHREF property. WebImageHREF returns a URL that identifies a specific image that is available as a simple file reference. If images must be generated dynamically in response to requests, then WebImageHREF returns false and the adapter dispatcher generates an HREF based on the request parameters supplied by the object that implements this interface.  

AHREF returns the URL that identifies the image of this field. 

WebImageHREF returns true if it supplies a URL as the value of the AHREF parameter, false if the HTML form must request images using a set of request parameters instead. 

EncodeAdapterItemRequestAsHREF