在WPF中使用EntityFrameWork加载数据时显示进度条

using System.Data.Entity;

// ...

private async void LoadData()
{
    // 显示进度条
    progressBar.Visibility = Visibility.Visible;

    // 创建Entity Framework上下文
    using (var context = new YourDbContext())
    {
        // 异步加载数据
        var data = await context.YourEntities.ToListAsync();

        // 将数据绑定到展示控件
        dataGrid.ItemsSource = data;
    }

    // 隐藏进度条
    progressBar.Visibility = Visibility.Collapsed;
}

public MainWindow()
{
    InitializeComponent();

    LoadData();
}