SharePoint Foundation’s SPList API now contain’s a method which can be used to retrieve a SPList’s “Related Fields”. This method returns a collection of SPRelatedFields representing all the Lookup Columns pointing to the SPList in question. This methods can be used as the basis for writing a useful extension method on SPList which retrieves a collection, specifically in this case a generic List<SPListItem>.
The Code Snippet below shows the code that will ultimately return the entire collection of ListItems that related to the SPListItem the method is called on:
The following Code Snippet demonstrates usage of this extension method in a Console Application. The ConsoleApplication is targeting a SPWeb that has 3 lists. The List titled “Target” is reference by two related lists:
The image below shows the console output when the code above is run:
