Object reference exception

Question

Hi Experts,

 

I want to create a new customer whose name already exists from a list of contacts.

Once the customer entity has been created, a receivable and possibly a payable account is also created.

But an exception is thrown with a message "Object reference not set to an instance of an object."

on examining further, I find these messages shown below but I don't know how to solve this problem.

 

'entity.PayableAccount' threw an exception of type 'System.ArgumentNullException'

 'entity.ReceivableAccount' threw an exception of type 'System.ArgumentNullException'

 

 

below is the UI that enables a new customer to be added from a list on contacts

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Linq;

using System.Threading.Tasks;

using System.Windows.Forms;

using DevExpress.XtraEditors;

using MakGarm.Business;

using MakGarm.Business.Contracts;

using MakGarm.Common.Entities.Core;

using Microsoft.Practices.Unity;

namespace MakGarm.Start.Customers {

public partial class frmAddCustomer : DevExpress.XtraEditors.XtraForm {

private ICustomerService _customerService;

private Customer _customer;

private IContactService _contactService;

//private Contact _contact;

public frmAddCustomer() {

InitializeComponent();

_customerService = UnityConfig.GetContainer().Resolve<ICustomerService>();

_contactService = UnityConfig.GetContainer().Resolve<IContactService>();

_customer = new Customer() {

Active = true,

Accountclosed = false,

Datecreated = DateTime.Now,

CreditDays = 0,

CreditLimit = 0,

LastEditedDate = DateTime.Now,

CompanyBranchId = CurrentUserInfo.User.CompanyBranch.CompanyId,

CheckerUserId = CurrentUserInfo.User.UserId

};

}

private void frmAddCustomer_Load(object sender, EventArgs e){

customerBindingSource.DataSource = _customer;

ContactBindingSource.DataSource = _contactService.GetAll();

}

private void Acccept_Click(object sender, EventArgs e) {

customerBindingSource.EndEdit();

_customerService.Insert(_customer);

}

}

}

the service (_customerService) that the Acccept_Click uses is shown below.

using System;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using MakGarm.Business.Contracts;

using MakGarm.Common.Entities.Core;

using MakGarm.Common.Entities.SubsidiaryLedgerAccounts;

using MakGarm.Common.Enums;

using MakGarm.Persistence.Contracts;

using Uwapi.Utils.Data;

namespace MakGarm.Business.Logic {

public class CustomerService : ICustomerService {

private readonly ICustomerRepository _CustomerRepository;

private readonly ICompanyRepository _companyRepository;

private readonly IFinancialYearService _financialYearService;

private readonly IContactRepository _contactRepository;

private readonly IUnitOfWork _unitOfWork;

public CustomerService(

ICustomerRepository customerRepository,

ICompanyRepository companyRepository,

IFinancialYearService financialYearService,

IContactRepository contactRepository,

IUnitOfWork unitOfWork) {

_CustomerRepository = customerRepository;

_companyRepository = companyRepository;

_financialYearService = financialYearService;

_contactRepository = contactRepository;

_unitOfWork = unitOfWork;

}

public void Insert(Customer entity) {

var company = _companyRepository.GetAll().First();

var contact = entity.Contact ?? _contactRepository.GetById(entity.ContactId);

entity.ContactRelationAccounts = new Collection<ContactRelationAccount>() {

new PayableContactRelationAccount() {

OpeningDate = _financialYearService.GetDbServerTime(),// AccountBalance = 0,

Active = true,

Type = SubsidiaryLedgerAccountTypeEnum.CustomerReceivable,

BaseAccountType = BaseAccountTypeEnum.Liability,

SubsidiaryLedgerAccountName = string.Format("{0} (Deposit Holding)", contact.ContactName),

Creator = entity.LastEditor,

OpeningBalance = 0,

Description = string.Format("{0} (Deposit Holding)", contact.ContactName),

IsSystemManaged = true,

ControlGeneralLedgerAccountId = company.CreditorsAccountPayableAccountId,},

new ReceivableContactRelationAccount() {

OpeningDate = _financialYearService.GetDbServerTime(),

AccountBalance = 0,

Active = true,

Type = SubsidiaryLedgerAccountTypeEnum.CustomerReceivable,

BaseAccountType = BaseAccountTypeEnum.Asset,

SubsidiaryLedgerAccountName = string.Format("{0} (Receivable)",contact.ContactName),

Creator = entity.LastEditor,

OpeningBalance = 0,

Description = string.Format("{0} (Receivable)", contact.ContactName),

IsSystemManaged = true,

ControlGeneralLedgerAccountId = company.CustomersAccountReceivableAccountId,

},

};

_CustomerRepository.Add(entity);

_unitOfWork.Commit();

}

public void Update(Customer entity) {

_CustomerRepository.Update(entity);

_unitOfWork.Commit();

}

public Customer GetById(int customerId) {

return _CustomerRepository.GetById(customerId);

}

public void Delete(int customerId) {

var branch = _CustomerRepository.GetById(customerId);

branch.DeletedStatus = true;

_CustomerRepository.Update(branch);

_unitOfWork.Commit();

}

public IEnumerable<Customer> GetAll() {

return _CustomerRepository.GetMany(s => s.DeletedStatus == false);

}

public IEnumerable<Customer> GetByCompanyBranchId(int companyBranchId) {

return _CustomerRepository.GetMany(b => b.CompanyBranchId == companyBranchId);

}

}

}

 

and below is the entity used.

 

 

using System;

using System.Collections.Generic;

using System.ComponentModel.DataAnnotations;

using System.ComponentModel.DataAnnotations.Schema;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using MakGarm.Common.Entities.Core;

using MakGarm.Common.Entities.Miscellaneous;

using MakGarm.Common.Entities.Documents;

using MakGarm.Common.Entities.SubsidiaryLedgerAccounts;

using MakGarm.Common.Enums;

namespace MakGarm.Common.Entities.Core {

public class Customer : ContactRelation {

#region Primitive Properties

public bool Active { get; set; }

public bool Accountclosed { get; set; }

public DateTime Datecreated { get; set; }

public int CreditDays { get; set; }

public int CreditLimit { get; set; }

[StringLength(255, ErrorMessage = "255 characters max")]

public string Remarks { get; set; }

public DateTime LastEditedDate { get; set; }

#region Foreign Keys

public int CompanyBranchId { get; set; }

public int? CheckerUserId { get; set; }

public int BillingStartFinancialMonthId { get; set; }

#endregion Foreign Keys

#endregion Primitive Properties

#region Navigation Properties

#region Parents

[ForeignKey("BillingStartFinancialMonthId")]

public virtual FinancialMonth BillingStartFinancialMonth { get; set; }

[ForeignKey("CompanyBranchId")]

public virtual CompanyBranch CompanyBranch { get; set; }

[ForeignKey("CheckerUserId")]

public virtual User Checker { get; set; }

#endregion Parents

#region Children

[InverseProperty("Customer")]

public virtual ICollection<CustomerInvoice> CustomerInvoices { get; set; }

[InverseProperty("Customer")]

public virtual ICollection<CustomerReceipt> CustomerReceipts { get; set; }

[NotMapped]public PayableContactRelationAccount PayableAccount {

get {

return ContactRelationAccounts.OfType<PayableContactRelationAccount>().FirstOrDefault();

}

}

[NotMapped]

public ReceivableContactRelationAccount ReceivableAccount {

get {

return ContactRelationAccounts.OfType<ReceivableContactRelationAccount>().FirstOrDefault();

}

}

#endregion Children

#endregion Navigation Properties

}

}

 

 

 

Please assist me. Thanks