如何刷新wpf中的ItemsControl以显示进度条动画

<Grid>
    <Grid.Resources>
        <DataTemplate x:Key="ItemTemplate">
            <!-- 定义每个数据项的外观 -->
        </DataTemplate>
    </Grid.Resources>

    <ItemsControl ItemsSource="{Binding DataItems}" ItemTemplate="{StaticResource ItemTemplate}">
        <!-- 定义ItemsControl的外观 -->
    </ItemsControl>

    <ProgressBar IsIndeterminate="True" Visibility="{Binding IsLoading, Converter={StaticResource BoolToVisibilityConverter}}" />
</Grid>

public class ProgressViewModel : INotifyPropertyChanged
{
    private bool isLoading;
    public bool IsLoading
    {
        get { return isLoading; }
        set
        {
            isLoading = value;
            OnPropertyChanged(nameof(IsLoading));
        }
    }

    private ObservableCollection<DataItem> dataItems;
    public ObservableCollection<DataItem> DataItems
    {
        get { return dataItems; }
        set
        {
            dataItems = value;
            OnPropertyChanged(nameof(DataItems));
        }
    }

    // 实现INotifyPropertyChanged接口的代码
}

public class DataItem
{
    // 数据项的属性和逻辑
}