How to open an item from Listview in new window and edit it?

Question

Related to the question here (how-to-update-listview-using-mvvm-pattern-and-obse.html), I would like to know how to do the following:

1) Save the list of users in database? (The Database should update itself when adding, editing or deleting items in the listview).
2) Open the selected item in Window1 and edit it and then save it again?
3) The window should be closed after clicking the save button. How should this be done?

Answer

Hi Juliette,
I build a Core5 demo with ADO.NET. Try it:

XAML MainWindow:

XAML DetailWindow:

and code:

using System;  
using System.Collections.ObjectModel;  
using System.ComponentModel;  
using System.Data;  
using System.Data.SqlClient;  
using System.Runtime.CompilerServices;  
using System.Windows;  
using System.Windows.Data;  
using System.Windows.Input;  
using WpfApp1;  
  
namespace WpfApp007  
{  
  public class ViewModel : INotifyPropertyChanged  
  {  
    Model model = new Model(WpfApp1.Properties.Settings.Default.cnSQL);  
    private CollectionViewSource cvs = new CollectionViewSource();  
    public ICollectionView View { get => cvs.View; }  
  
    public ICommand Cmd { get => new RelayCommand(CmdExec, CanCmdExec); }  
  
    private void CmdExec(object obj)  
    {  
      try  
      {  
        IsWorking = true;  
        switch (obj.ToString())  
        {  
          case "Load":  
            model.LoadData();  
            cvs.Source = model.GetData();  
            OnPropertyChanged(nameof(View));  
            Status = "Data loaded!";  
            break;  
          case "Add":  
            ViewModelDetail vm = new ViewModelDetail() { Row = model.GetNewData() };  
            Window007Detail wnd = new Window007Detail() { DataContext = vm };  
            if (wnd.ShowDialog().Value) model.AddData(vm.Row);  
            Status = "Data added!";  
            break;  
          case "Create":  
            model.Create();  
            Status = "DataTable created!";  
            break;  
          default:  
            break;  
        }  
      }  
      catch (Exception ex) { Status = ex.Message; }  
      finally { IsWorking = false; }  
    }  
  
    private bool CanCmdExec(object obj) => !IsWorking;  
  
    public ICommand Edit { get => new RelayCommand(CmdEdit, CanCmdExec); }  
  
    private void CmdEdit(object obj)  
    {  
      IsWorking = true;  
      ViewModelDetail vm = new ViewModelDetail() { Row = (Data)obj };  
      Window007Detail wnd = new Window007Detail() { DataContext = vm };  
      if (wnd.ShowDialog().Value) model.SaveData(); else model.RejectData();  
      IsWorking = false;  
    }  
  
    public ICommand Delete { get => new RelayCommand(CmdCancel, CanCmdExec); }  
  
    private void CmdCancel(object obj)  
    {  
      IsWorking = true;  
      model.DeleteData((Data)obj);  
      IsWorking = false;  
    }  
  
    private bool _isWorking = false;  
    private bool IsWorking  
    {  
      get => this._isWorking;  
      set { this._isWorking = value; OnPropertyChanged(nameof(Cmd)); }  
    }  
  
    private string _status;  
    public string Status  
    {  
      get => this._status;  
      set { this._status = value; OnPropertyChanged(); }  
    }  
  
    public event PropertyChangedEventHandler PropertyChanged;  
    private void OnPropertyChanged([CallerMemberName] string propName = "") => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));  
  }  
  
  public class ViewModelDetail : ICommand  
  {  
    public Data Row { get; set; }  
    public Window Wnd;  
  
    public static readonly DependencyProperty AttPropProperty =  
        DependencyProperty.RegisterAttached("AttProp", typeof(bool), typeof(ViewModelDetail), new PropertyMetadata(false, OnPropChanged));  
    public static bool GetAttProp(DependencyObject obj) => (bool)obj.GetValue(AttPropProperty);  
    public static void SetAttProp(DependencyObject obj, bool par) => obj.SetValue(AttPropProperty, par);  
    private static void OnPropChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)  
    {  
      Window wnd = d as Window;  
      if (wnd == null) return;  
      wnd.Loaded += (s,e) => ((ViewModelDetail)(wnd.DataContext)).Wnd = wnd;  
    }  
  
    public event EventHandler CanExecuteChanged;  
    public bool CanExecute(object parameter) => true;  
    public void Execute(object parameter)  
    {  
      switch (parameter.ToString())  
      {  
        case "Save":  
          Wnd.DialogResult = true;  
          Wnd.Close();  
          break;  
        case "Cancel":  
          Wnd.DialogResult = false;  
          Wnd.Close();  
          break;  
        default:  
          break;  
      }  
    }  
  }  
  
  public class Model  
  {  
    public Model(string connectionString) => cnString = connectionString;  
    string cnString;  
  
    private DataTable dt = new DataTable();  
    string sqlSelect = "SELECT * FROM Table1";  
  
    ObservableCollection col = new ObservableCollection();  
  
    internal ObservableCollection GetData()  
    {  
      col.Clear();  
      foreach (DataRow row in dt.Rows) col.Add(new Data(row));  
      return col;  
    }  
  
    internal Data GetNewData() => new Data(dt.NewRow());  
  
    internal void AddData(Data d)  
    {  
      dt.Rows.Add(d.row);  
      SaveData();  
      col.Add(d);  
    }  
  
    internal void RejectData() => dt.RejectChanges();  
  
    internal void LoadData()  
    {  
      using (SqlConnection cn = new SqlConnection(cnString))  
      using (SqlDataAdapter da = new SqlDataAdapter(sqlSelect, cn))  
        da.Fill(dt);  
    }  
  
    internal void DeleteData(Data d)  
    {  
      d.row.Delete();  
      SaveData();  
      col.Remove(d);  
    }  
  
    internal void SaveData()  
    {  
      using (SqlConnection cn = new SqlConnection(cnString))  
      using (SqlDataAdapter da = new SqlDataAdapter(sqlSelect, cn) { AcceptChangesDuringUpdate = true })  
      {  
        da.RowUpdated += (s, e) =>  
        {  
          SqlCommand idCmd = new SqlCommand("SELECT @@IDENTITY", e.Command.Connection);  
          if (e.StatementType == StatementType.Insert)  
          {  
            var newID = idCmd.ExecuteScalar();  
            foreach (DataColumn col in e.Row.Table.Columns)  
              if (col.AutoIncrement)  
              {  
                e.Row[col.ColumnName] = newID;  
                break;  
              }  
          }  
        };  
        SqlCommandBuilder cb = new SqlCommandBuilder(da);  
        da.Update(dt);  
      }  
    }  
  
    internal void Create()  
    {  
      using (SqlConnection cn = new SqlConnection(cnString))  
      {  
        cn.Open();  
        using (SqlCommand cmd = new SqlCommand("", cn))  
        {  
          // delete previous table in SQL Server 2016 and above  
          cmd.CommandText = "DROP TABLE IF EXISTS Table1;";  
          cmd.ExecuteNonQuery();  
          // Create Table  
          cmd.CommandText = "CREATE Table [Table1]([ID] int Identity, [Name] nvarchar(255), CONSTRAINT [PK_Table1] PRIMARY KEY ([ID]))";  
          cmd.ExecuteNonQuery();  
          // demo Data  
          cmd.CommandText = "INSERT Table1(Name) VALUES('Name 1');";  
          cmd.ExecuteNonQuery();  
        }  
      }  
    }  
  }  
  
  public class Data  
  {  
    public Data(DataRow datarow) => row = datarow;  
    public DataRow row;  
    public int ID { get => row.Field("ID"); set { row["ID"] = value; } }  
    public string Name { get => row.Field("Name"); set { row["Name"] = value; } }  
  }  
  
  public class RelayCommand : ICommand  
  {  
    private readonly Predicate

Answer

Hi Juliette,
you can use separate buttons in Window for Edit and Delete selected row in DataGrid. Try following demo (Window008 with part of last demo).

and ViewModel:

using System;  
using System.ComponentModel;  
using System.Runtime.CompilerServices;  
using System.Windows;  
using System.Windows.Data;  
using System.Windows.Input;  
using WpfApp007;  
using WpfApp1;  
  
namespace WpfApp008  
{  
  public class ViewModel : INotifyPropertyChanged  
  {  
    Model model = new Model(WpfApp1.Properties.Settings.Default.cnSQL);  
    private CollectionViewSource cvs = new CollectionViewSource();  
    public ICollectionView View { get => cvs.View; }  
  
    public object SelectedItem { get; set; }  
  
    public ICommand Cmd { get => new RelayCommand(CmdExec, CanCmdExec); }  
  
    private void CmdExec(object obj)  
    {  
      try  
      {  
        IsWorking = true;  
        switch (obj.ToString())  
        {  
          case "Load":  
            model.LoadData();  
            cvs.Source = model.GetData();  
            OnPropertyChanged(nameof(View));  
            Status = "Data loaded!";  
            break;  
          case "Add":  
            ViewModelDetail vm = new ViewModelDetail() { Row = model.GetNewData() };  
            Window007Detail wnd = new Window007Detail() { DataContext = vm };  
            if (wnd.ShowDialog().Value) model.AddData(vm.Row);  
            Status = "Data added!";  
            break;  
          case "Create":  
            model.Create();  
            Status = "DataTable created!";  
            break;  
          default:  
            break;  
        }  
      }  
      catch (Exception ex) { Status = ex.Message; }  
      finally { IsWorking = false; }  
    }  
  
    private bool CanCmdExec(object obj) => !IsWorking;  
  
    public ICommand Edit { get => new RelayCommand(CmdEdit, CanCmdExec); }  
  
    private void CmdEdit(object obj)  
    {  
      Data d = SelectedItem as Data;  
      if (d == null) return;  
      IsWorking = true;  
      ViewModelDetail vm = new ViewModelDetail() { Row = d};  
      Window007Detail wnd = new Window007Detail() { DataContext = vm };  
      if (wnd.ShowDialog().Value) model.SaveData(); else model.RejectData();  
      IsWorking = false;  
    }  
  
    public ICommand Delete { get => new RelayCommand(CmdDelete, CanCmdExec); }  
  
    private void CmdDelete(object obj)  
    {  
      Data d = SelectedItem as Data;  
      if (d == null) return;  
      IsWorking = true;  
      model.DeleteData(d);  
      IsWorking = false;  
    }  
  
    private bool _isWorking = false;  
    private bool IsWorking  
    {  
      get => this._isWorking;  
      set { this._isWorking = value; OnPropertyChanged(nameof(Cmd)); }  
    }  
  
    private string _status;  
    public string Status  
    {  
      get => this._status;  
      set { this._status = value; OnPropertyChanged(); }  
    }  
  
    public event PropertyChangedEventHandler PropertyChanged;  
    private void OnPropertyChanged([CallerMemberName] string propName = "") => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));  
  }  
}

Result:

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How to open an item from Listview in new window and edit it?

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