WPF DataGrid如何从实体框架刷新项目源

Question

I am wondering if there is a correct or sensible way of refreshing a DataGrid ItemSource from Entity Framework (ie the Database)

I need to get the latest data from the table in the database as the data is being populated via a web service and not the WPF app itself.

I have used DataGrid.Items.Refresh() but to no prevail.

I could assign the Property of the Itemsource again, but then I need an event to happen on the datagrid to cause the update (unless that is wrong)

Anyone have any suggestions?

Thanks

Answer 1

You just need to bind the DataGrid properly.

<Window DataContext="{Binding RelativeSource={RelativeSource Self}}">
    <StackPanel>
        <Button Content="Refresh" Click="Refresh_Click" />
        <DataGrid ItemsSource="{Binding Items}"></DataGrid>
    </StackPanel>
</Window>

Then clear the data binding and re-add the items, the UI will be updated automatically.

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }
    private readonly ObservableCollection<Item> _items = new ObservableCollection<Item>();
    public ObservableCollection<Item> Items
    {
        get { return _items; }
    }
    private void Refresh_Click(object sender, RoutedEventArgs e)
    {
        using (var context = new AppContext())
        {
            var items = context.Items.ToArray();

            // Clears the item source then re-add all items.
            Items.Clear();
            Array.ForEach(items, Items.Add);
        }
    }
}