private async void GetSelectedButton_Click(object sender, EventArgs e)
{
ResultsTextBox.Text = "";
var sb = new StringBuilder();
/*
* Get all checked categories primary key in the checked list box
*/
var indices = CategoryCheckedListBox.SelectedCategoryIdentifier();
if (indices.Length <= 0)
{
return;
}
using (var context = new NorthWindContext())
{
/*
* Get all products for each category, not FindAllAsync expects an
* object array not an int array so they are converted via
* Array.ConvertAll.
*/
Categories[] categories = await context.FindAllAsync <Categories>(Array.ConvertAll(indices, id => (object)id));
/*
* Display in a text box
*/
foreach (Categories category in categories)
{
sb.AppendLine(category.CategoryName);
List <Products> products = context.Products
.AsNoTracking().Where(prod => prod.CategoryId == category.CategoryId)
.ToList();
foreach (Products product in products)
{
sb.AppendLine($" {product.ProductId,-4}{product.ProductName}");
}
sb.AppendLine();
}
ResultsTextBox.Text = sb.ToString();
}
}
