问在linq选择问题中异步等待导出csv

EN

private async Task<IEnumerable> OnExport(SearchCriteria cr)
    {
        var sr = await GetResult(cr);
        var results = sr.Results;
        var exportData = results.Select(async export =>
        {
            var data = await dataService.GetById(export.Id);
            var pAddress = export.ContactInformation?.Addresses.FirstOrDefault(x => x.AddressType == Framework.Contracts.Enums.AddressTypes.Physical);
            var mAddress = export.ContactInformation?.Addresses.FirstOrDefault(x => x.AddressType == Framework.Contracts.Enums.AddressTypes.Mailing);
            return new
            {
                LegalBusinessName = export.Name,
                DBA = export.DBAName,
                BusinessEmail = export.ContactInformation?.PrimaryEmail,
                PhonePrimary = export.ContactInformation?.PrimaryPhone,
                PhoneTypePrimary = export.ContactInformation?.PrimaryPhoneType,
                PhoneSecondary = export.ContactInformation?.SecondaryPhone,
                PhoneTypeSecondary = export.ContactInformation?.SecondaryPhoneType,
                Website = export.WebAddress,
                PhysicalStreetAddress = pAddress?.Address1,
                PhysicalAddressLine2 = pAddress?.Address2,
                PhysicalCity = pAddress?.City,
                PhysicalCounty = pAddress?.County,
                PhysicalState = pAddress?.State,
                PhysicalZipCode = pAddress?.Zip,
                MailingStreetAddress = mAddress?.Address1,
                MailingAddressLine2 = mAddress?.Address2,
                MailingCity = mAddress?.City,
                MailingCounty = mAddress?.County,
                MailingState = mAddress?.State,
                MailingZipCode = mAddress?.Zip,
                SchoolOnboarding = data?.ConfirmedVideo,
                SchoolStartDate = data?.SchoolStartDate,
                SchoolEndDate = data?.SchoolEndDate,
                Grades = string.Join(",", data?.GradeLevels.Select(x => x.GradeLevel)),
                IsReligiousSchool = data?.ConfirmedIsReligious,
                ReligiousAffiliation = data?.ReligiousAffiliation,
                TCSignatureName = export.SignatureName,
                TCDateSigned = export.TermsAcceptedOn
            };
        });

        return exportData;
    }