DataGrid CRUD(MVVM模式)

引用程序包：MvvmLight

实体类：

 public class Student : ViewModelBase
    {
        private int id;
        private string name;

        public int Id
        {
            get { return id; }
            set
            {
                id = value;
                RaisePropertyChanged();
            }
        }
        public string Name
        {
            get { return name; }
            set
            {
                name = value;
                RaisePropertyChanged();
            }
        }
        public Student Clone()
        {
            return this.MemberwiseClone() as Student;
        }
    }

　　数据库类：

 public class StudentDb
    {
        public StudentDb()
        {
            Init();
        }
        private List<Student> m_Students = new List<Student>();
        private void Init()
        {
            for (int i = 0; i < 30; i++)
            {
                m_Students.Add(new Student()
                {
                    Id = i,
                    Name = $"姓名{i}"
                });
            }
        }

        public List<Student> GetStudents()
        {
            return m_Students;
        }
        public void AddStudent(Student student)
        {
            m_Students.Add(student);
        }
        public void DelStudent(int id)
        {
            var model=m_Students.FirstOrDefault(x => x.Id == id);
            if (model != null)
            {
                m_Students.Remove(model);
            }
        }
        public List<Student> GetStudentByName(string name)
        {
            if(string.IsNullOrEmpty(name))
            {
                return m_Students;
            }
            return m_Students.Where(m=>m.Name.Contains(name)).ToList();
        }
        public int GetId()
        {
            return m_Students.Max(m => m.Id) + 1;
        }
        public Student? GetModel(int id)
        {
            return m_Students.FirstOrDefault(m => m.Id == id).Clone();
        }


    }

　　ViewModel类

 public class MainViewModel : ViewModelBase
    {
        StudentDb db;
        private ObservableCollection<Student> gridModelList;
        private string search;
        public MainViewModel()
        {
            db = new StudentDb();
            QueryCommand = new RelayCommand(Query);
            ResetCommand = new RelayCommand(Reset);
            AddCommand = new RelayCommand(Add);
            EditCommand = new RelayCommand<int>(Edit);
            DeleteCommand = new RelayCommand<int>(m => Delete(m));
        }
        public ObservableCollection<Student> GridModelList
        {
            get { return gridModelList; }
            set
            {
                gridModelList = value;
                RaisePropertyChanged();
            }
        }
        //搜索条件
        public string Search
        {
            get { return search; }
            set { search = value; RaisePropertyChanged(); }
        }
        public void Query()
        {
            GridModelList = new ObservableCollection<Student>();
            var models = db.GetStudentByName(search);
            if (models != null)
            {
                models.ForEach(m => GridModelList.Add(m));
            }
        }
        public void Reset()
        {
            Search = string.Empty;
            Query();
        }
        public void Add()
        {
            Student student = new Student();
            StudentEdit view = new StudentEdit(student);
            var result = view.ShowDialog();
            if (result.HasValue && result.Value)
            {
                student.Id = db.GetId();
                db.AddStudent(student);
                gridModelList.Add(student);
            }
        }
        public void Edit(int id)
        {
            var model = db.GetModel(id);
            if (model != null)
            {
                StudentEdit view = new StudentEdit(model);
                var result = view.ShowDialog();
                if (result.HasValue && result.Value)
                {
                    var oldModel = GridModelList.FirstOrDefault(m => m.Id == id);
                    if (oldModel != null)
                    {
                        oldModel.Name = model.Name;
                    }
                }
            }
        }
        public void Delete(int id)
        {
            var model = db.GetModel(id);
            if (model != null)
            {
                var result = MessageBox.Show($"是否删除当前行学生:{model.Name}?", "删除", MessageBoxButton.OKCancel, MessageBoxImage.Question);
                if (result == MessageBoxResult.OK)
                {
                    db.DelStudent(id);
                    var oldModel = GridModelList.FirstOrDefault(m => m.Id == id);
                    if (oldModel != null)
                    {
                        GridModelList.Remove(oldModel);
                    }
                }
            }
        }
        #region Command
        public RelayCommand QueryCommand { get; set; }
        public RelayCommand ResetCommand { get; set; }
        public RelayCommand AddCommand { get; set; }
        public RelayCommand<int> EditCommand { get; set; }
        public RelayCommand<int> DeleteCommand { get; set; }
        #endregion



    }

　　主窗口XML

<Window x:Class="WpfApp1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp1"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="820"
        Loaded="Window_Loaded"
        >
  
    <Grid Margin="5">
        <Grid.RowDefinitions>
            <RowDefinition Height="60"></RowDefinition>
            <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
        <StackPanel Orientation="Horizontal">
            <TextBlock Text="搜索条件：" VerticalAlignment="Center"/>
            <TextBox Text="{Binding Search}" Width="200" Height="25" Margin="10,0,0,0"/>
            <Button Content="查找" Command="{Binding QueryCommand}" Width="70" Height="25" Margin="10,0,0,0"/>
            <Button Content="重置" Command="{Binding ResetCommand}" Width="70" Height="25" Margin="10,0,0,0"/>
            <Button Content="新增" Command="{Binding AddCommand}" Width="70" Height="25" Margin="10,0,0,0"/>
        </StackPanel>
        <DataGrid Grid.Row="1" ColumnWidth="*" AutoGenerateColumns="False" CanUserAddRows="False" ItemsSource="{Binding GridModelList}">
            <DataGrid.Columns>
                <DataGridTextColumn Header="序号" Binding="{Binding Id}"/>
                <DataGridTextColumn Header="姓名" Binding="{Binding Name}"/>
                <DataGridTemplateColumn Header="操作">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <StackPanel Orientation="Horizontal">
                                <Button Content="修改" CommandParameter="{Binding Id}" Command="{Binding DataContext.EditCommand,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=DataGrid}}" Width="60" Height="25" Background="White" Foreground="Black"/>
                                <Button Content="删除" CommandParameter="{Binding Id}" Command="{Binding DataContext.DeleteCommand,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=DataGrid}}" Width="60" Height="25" Background="Red" Foreground="White"/>
                            </StackPanel>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>
            </DataGrid.Columns>
            
        </DataGrid>
                  
    </Grid>
  

</Window>

　　主窗口后台文件 

 public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            MainViewModel viewModel=new MainViewModel();
            viewModel.Query();
            this.DataContext = viewModel;
        }
    }

　　编辑窗口XML

<Window x:Class="WpfApp1.Views.StudentEdit"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp1.Views"
        mc:Ignorable="d"
        Title="StudentEdit" Height="350" Width="400"
        WindowStyle="None" AllowsTransparency="False" WindowStartupLocation="CenterScreen">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="60"></RowDefinition>
            <RowDefinition></RowDefinition>
            <RowDefinition Height="60"></RowDefinition>
        </Grid.RowDefinitions>
        <TextBlock Text="编辑学习信息" FontWeight="Bold" FontSize="30"
                   Margin="10,0,0,0" VerticalAlignment="Center"/>
        <StackPanel Grid.Row="1" HorizontalAlignment="Center" VerticalAlignment="Center">
            <TextBlock Text="姓名:" VerticalAlignment="Center"/>
            <TextBox Text="{Binding Model.Name}" Width="200" Height="25"/>
        </StackPanel>
        <StackPanel Orientation="Horizontal" Grid.Row="2" HorizontalAlignment="Right">
            <Button x:Name="ok" Width="70" Height="25" Content="确定" Click="ok_Click"/>
            <Button x:Name="cancel" Width="70" Height="25" Content="取消" Click="cancel_Click" Margin="10,0,10,0"/>
        </StackPanel>
    </Grid>
</Window>

　　编辑窗口后台

 public partial class StudentEdit : Window
    {
        public StudentEdit(Student student)
        {
            InitializeComponent();
            this.DataContext=new {Model= student};
        }

        private void ok_Click(object sender, RoutedEventArgs e)
        {
            this.DialogResult = true; 
            this.Close();
        }

        private void cancel_Click(object sender, RoutedEventArgs e)
        {
            this.DialogResult = false;
            this.Close();
        }
    }