when i add new item to observablecollection is not sync to datagrid

Test it

MainWindow.xaml:

MainViewModel.cs
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows.Input;
namespace ObservableCollectionDemo;
public class MainViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler? PropertyChanged;
public ObservableCollection Data { get; set; }
public ICommand AddDataCommand { get; set; }
public MainViewModel()
{
Random r = new Random();
Data = new ObservableCollection();
AddDataCommand = new RelayCommand(() =>
{
Data data = new Data
{
Col1 = r.Next(),
Col2 = r.Next(),
Col3 = r.Next()
};
Data.Add(data);
});
}
protected virtual void OnPropertyChanged([CallerMemberName] string? propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
protected bool SetField(ref T field, T value, [CallerMemberName] string? propertyName = null)
{
if (EqualityComparer.Default.Equals(field, value)) return false;
field = value;
OnPropertyChanged(propertyName);
return true;
}
}
public class Data
{
public int Col1 { get; set; }
public int Col2 { get; set; }
public int Col3 { get; set; }
}
public class RelayCommand : ICommand
{
private readonly Action _action;
public RelayCommand(Action action)
{
_action = action;
}
public bool CanExecute(object? parameter)
{
return true;
}
public void Execute(object? parameter)
{
_action.Invoke();
}
public event EventHandler? CanExecuteChanged;
}