如何在按钮命令wpf中填充数据到数据网格？

<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="450" Width="800">
    <Window.DataContext>
        <local:MainViewModel/>
    </Window.DataContext>
    <Grid>
        <Button Content="Load Data" Command="{Binding LoadDataCommand}"/>
        <DataGrid ItemsSource="{Binding DataItems}" AutoGenerateColumns="True"/>
    </Grid>
</Window>

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using GalaSoft.MvvmLight.Command;

public class MainViewModel : INotifyPropertyChanged
{
    private ObservableCollection<DataItem> _dataItems;
    public ObservableCollection<DataItem> DataItems
    {
        get => _dataItems;
        set
        {
            _dataItems = value;
            OnPropertyChanged();
        }
    }

    public RelayCommand LoadDataCommand { get; set; }

    public MainViewModel()
    {
        DataItems = new ObservableCollection<DataItem>();
        LoadDataCommand = new RelayCommand(LoadData);
    }

    private void LoadData()
    {
        // 这里是加载数据的逻辑，例如从数据库或服务获取数据
        var data = new List<DataItem>
        {
            new DataItem { Name = "Item 1", Value = 100 },
            new DataItem { Name = "Item 2", Value = 200 }
        };
        DataItems.Clear();
        foreach (var item in data)
        {
            DataItems.Add(item);
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

public class DataItem
{
    public string Name { get; set; }
    public int Value { get; set; }
}