musicschool/musicschoolapp/Pages/CourseEditingPage.xaml.cs

using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Data.Entity.Migrations;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using System.Linq;
using System.Runtime.Remoting.Contexts;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.IO;
using System.Data.Entity.Validation;

namespace musicschoolapp.Pages
{
    /// <summary>
    /// Логика взаимодействия для StudentEditingPage.xaml
    /// </summary>
    public partial class CourseEditingPage : Page
    {
        musicschoolEntities1 mse = new musicschoolEntities1();
        DbSet<Student> dbContext_;
        List<Course> students1;
        bool adding = false;
        public CourseEditingPage(bool editing)
        {
            InitializeComponent();
            students1 = mse.Course.ToList();
            dGridStudent.ItemsSource = students1;
            if(editing)
            {
                dGridStudent.IsReadOnly = false;
            }
            else
            {
                dGridStudent.IsReadOnly = true;
            }
        }


        public int updateDB()
        {
            try
            {
                foreach (var student in students1)
                {
                    var original = mse.Course.Find(student.CourseID);

                    if (original != null)
                    {
                        mse.Entry(original).CurrentValues.SetValues(student);
                    }
                    else
                    {
                        mse.Course.Add(student);
                    }
                }
                int saveresult = mse.SaveChanges();
                students1 = mse.Course.ToList();
                dGridStudent.ItemsSource=students1;
                return saveresult;
            }
            catch (Exception ex)
            {
                students1 = mse.Course.ToList();
                dGridStudent.ItemsSource = students1;
                return -1;
            }
        }
        private void dGridStudent_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            var grid = (DataGrid)sender;
            var cellInfo = grid.SelectedCells[grid.CurrentCell.Column.DisplayIndex];

            if (cellInfo.Column.Header.ToString() == "Фото")
            {
                if (MessageBox.Show("Вы дважды кликнули по столбцу 'Фото'. Изменить?", "Вопрос", MessageBoxButton.YesNo) == MessageBoxResult.Yes)
                {
                    OpenFileDialog openFileDialog = new OpenFileDialog();
                    openFileDialog.ShowDialog();
                    if (mse.Course.Find((grid.SelectedItem as Course).CourseID) == null)
                    {
                        MessageBox.Show("Объект не создан.");
                        grid.SelectedItem = -1;
                        mse.Course.Add(dGridStudent.SelectedItem as Course);
                        try
                        {
                            mse.SaveChanges();
                        }
                        catch (DbEntityValidationException ex)
                        {
                            foreach (var entityValidationErrors in ex.EntityValidationErrors)
                            {
                                foreach (var validationError in entityValidationErrors.ValidationErrors)
                                {
                                    MessageBox.Show("Свойство: " + validationError.PropertyName + " Ошибка: " + validationError.ErrorMessage);
                                }
                            }
                        }

                        MessageBox.Show("добавил");
                        int index = grid.SelectedIndex;
                        grid.SelectedIndex = -1;
                        grid.SelectedIndex = index;
                        dGridStudent_SelectionChanged(sender, new SelectionChangedEventArgs(DataGrid.SelectionChangedEvent, new Collection<object> { }, new Collection<object> { dGridStudent.SelectedItem }));
                    }
                    mse.SaveChanges();
                    dGridStudent.ItemsSource = mse.Course.ToList();
                }
            }
        }
        private void dGridStudent_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (e.AddedItems != null && e.AddedItems.Count > 0)
            {
               

            }
            else if (e.RemovedItems != null && e.RemovedItems.Count > 0)
            {

                Course selectedStudent = (e.RemovedItems[0] as Course);
                if (selectedStudent != null)
                {
                    Course studentInDb = mse.Course.Find(selectedStudent.CourseID);
                    if (studentInDb != null)
                    {
                        mse.Course.Remove(studentInDb);

                        try
                        {
                            mse.SaveChanges();
                        }
                        catch (DbUpdateException ex)
                        {

                            MessageBox.Show("Запись, похоже, удалить нельзя.\n\n" + ex.InnerException);
                            students1 = mse.Course.ToList();
                            mse.Entry(studentInDb).State = System.Data.EntityState.Unchanged;

                            return;
                        }
                        students1.Remove(dGridStudent.SelectedItem as Course);
                        dGridStudent.SelectedIndex = -1;
                        MessageBox.Show("Удалено");
                    }
                }
            }

        }
    }
}