System.Reflection.targetException：＆＃x27;非静态方法需要一个目标

Question

我会收到错误消息“ system.reflection.targetException：'非静态方法需要一个目标。”

子句中处理此对象

破裂是因为我试图在where （

）

ViewBag.LibraryTypeVersionID = (from ltv in _db.LibraryTypeVersions
                                            let schemeLibraries = _db.SchemeLibraryTypes
                                            .Where(x=> (scheme == null || x.IdScheme == scheme.IdScheme))
                                            .Select(x => x.IdLibraryTypeVersion).ToList()
                                            select new
                                            {
                                                LibraryName = ltv.LibraryType.LibraryName,
                                                IdLibraryTypeVersion = ltv.IdLibraryTypeVersion,
                                                Version = ltv.Version,
                                                SchemeIdLibraryVersion = schemeLibraries
                                            }).OrderByDescending(x => x.LibraryName)
                          .ToGroupedSelectList(
                x => x.LibraryName,
                x => x.LibraryName + " - " + x.Version,
                x => x.IdLibraryTypeVersion,
                x => x.SchemeIdLibraryVersion.Contains(x.IdLibraryTypeVersion));***emphasized text***

它