protected virtual bool IsItemContainer(IDataObject dataObject, IDesignerHost host) { if (dataObject == null) { throw new ArgumentNullException("dataObject"); } if (ToolboxItemContainer.ContainsFormat(dataObject)) { return(true); } ICollection creatorCollection = this.GetCreatorCollection(host); if (creatorCollection != null) { foreach (ToolboxItemCreator creator in creatorCollection) { if (dataObject.GetDataPresent(creator.Format)) { return(true); } } } return(false); }