Is a sublayout in use anywhere?

The following sample code may be useful if you want to know whether a sublayout is used anywhere.

   1: Sitecore.Context.SetActiveSite("shell");

   2: Database masterdb = Sitecore.Context.ContentDatabase;

   3:  

   4: // item for which we check sublayout reference

   5: Item item = masterdb.Items["/sitecore/content/home/test"];

   6:  

   7: // get Renderings field of the item

   8: string rend = item.Fields["__renderings"].Value;

   9: LayoutDefinition layout = LayoutDefinition.Parse(rend);

  10: DeviceItem dev = Sitecore.Context.Device;

  11: DeviceDefinition device = layout.GetDevice(dev.ID.ToString());

  12:  

  13: // the rendering which you want to check referrings to

  14: Item myrendering = masterdb.Items["/sitecore/layout/renderings/document"];

  15:  

  16: // get the rendering of our item

  17: RenderingDefinition rendering = device.GetRendering(myrendering.ID.ToString());

  18:  

  19: if(rendering != null){

  20:   Response.Write(String.Format("Item {0} links to the rendering {1}", item.Name, myrendering.Name));

  21: }

  22: else {

  23:   Response.Write(String.Format("Item {0} doesn't link to the rendering {1}", item.Name, myrendering.Name));

  24: }