public IEnumerable <License> GetAllLicensesEnum(string searchString) { IEnumerable <License> licenses = repository.GetAllLicensesEnum(); if (!string.IsNullOrEmpty(searchString)) { //Installed nuget package: NinjaNye.SearchExtensions (http://ninjanye.github.io/SearchExtensions/stringsearch.html) which works really good! licenses = licenses.Search(h => h.PurchaseItem.Product.Name ?? "", h => h.Status != null ? h.Status.Name : "", h => h.No ?? "", h => h.Key ?? "", h => h.LicenseType.Name ?? "", h => h.LicenseValidityType.Name ?? "") .Containing(searchString); } return(licenses); }