private async Task LoadDataForGenerate() { Year_SemesterDataService year_SemesterDataService = new Year_SemesterDataService(new EntityFramework.TimetableManagerDbContext()); List <Year_Semester> YsList = await year_SemesterDataService.GetYs(); List <string> YearNameList = new List <string>(); YsList.ForEach(e => { YearNameList.Add(e.YsShortName); }); ProgrammeDataService programmeDataService = new ProgrammeDataService(new EntityFramework.TimetableManagerDbContext()); List <Programme> programmeList = await programmeDataService.GetProgramme(); List <string> ProgrammeNameList = new List <string>(); programmeList.ForEach(e => { ProgrammeNameList.Add(e.ProgrammeShortName); }); GroupNumberDataService groupNumberDataService = new GroupNumberDataService(new EntityFramework.TimetableManagerDbContext()); List <GroupNumber> GroupNumberList = await groupNumberDataService.GetGroupNumbers(); List <string> GroupNameList = new List <string>(); GroupNumberList.ForEach(e => { GroupNameList.Add(e.GroupNum); }); SubGroupNumberDataService subGroupNumberDataService = new SubGroupNumberDataService(new EntityFramework.TimetableManagerDbContext()); List <SubGroupNumber> SubGroupNumberList = await subGroupNumberDataService.GetSubGroupNumbers(); List <string> SubGroupNameList = new List <string>(); SubGroupNumberList.ForEach(e => { SubGroupNameList.Add(e.SubGroupNum); }); List <string> GeneratedList = new List <string>(); YearNameList.ForEach(y => { ProgrammeNameList.ForEach(p => { GroupNameList.ForEach(g => { SubGroupNameList.ForEach(s => { string id = String.Concat(y, ".", p, ".", g, ".", s); GeneratedList.Add(id); }); }); }); }); GeneratedList.ForEach(async e => { _ = await groupIdDataService1.AddSubGroupId(new SubGroupId { SubGroupID = e }); SubGroupIdDataList.Add(new SubGroupId { SubGroupID = e }); }); }