ProjectLib/ProjectLibrary/Forms/FReaders.cs

using ProjectLibrary.Repositories;
using Unity;
using System;
using System.Windows.Forms;

namespace ProjectLibrary.Forms
{
    public partial class FReaders : Form
    {
        private readonly IUnityContainer _container;
        private readonly IReaderRepository _readerRepository;

        public FReaders(IUnityContainer container, IReaderRepository readerRepository)
        {
            InitializeComponent();
            _container = container ?? throw new ArgumentNullException(nameof(container));
            _readerRepository = readerRepository ?? throw new ArgumentNullException(nameof(readerRepository));
        }
        private void LoadList()
        {
            dataGridViewReaders.DataSource = _readerRepository.ReadReaders();
        }
        private void FReaders_Load(object sender, EventArgs e)
        {
            try
            {
                LoadList();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Ошибка при загрузке", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }

        private void ButtonAdd_Click(object sender, EventArgs e)
        {
            try
            {
                _container.Resolve<FReader>().ShowDialog();
                LoadList();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Ошибка при добавлении", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }

        private void ButtonRemove_Click(object sender, EventArgs e)
        {
            if (!TryGetIdentifierFromSelectedRow(out var findId))
            {
                return;
            }

            if (MessageBox.Show("Удалить запись?", "Удаление", MessageBoxButtons.YesNo) != DialogResult.Yes)
            {
                return;
            }

            try
            {
                _readerRepository.DeleteReader(findId);
                LoadList();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Ошибка при удалении", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }

        private void ButtonUpdate_Click(object sender, EventArgs e)
        {
            if (!TryGetIdentifierFromSelectedRow(out var findId))
            {
                return;
            }

            try
            {
                var form = _container.Resolve<FReader>();
                form.ID = findId;
                form.ShowDialog();
                LoadList();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Ошибка при изменении", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }

        private bool TryGetIdentifierFromSelectedRow(out int id)
        {
            id = 0;
            if (dataGridViewReaders.SelectedRows.Count < 1)
            {
                MessageBox.Show("Нет выбранной записи", "Ошибка", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return false;
            }

            id = Convert.ToInt32(dataGridViewReaders.SelectedRows[0].Cells["Id"].Value);
            return true;
        }
    }
}