private void FrmProducts_Load(object sender, EventArgs e)
 {
     using (var db = new NORTHWNDEntities())
     {
         cmbCategory.DataSource = db.Categories.ToList();
         cmbSupplier.DataSource = db.Suppliers.ToList();
     }
 }
        private void btnShowReport_Click(object sender, EventArgs e)
        {
            Category category = cmbCategory.SelectedItem as Category;
            Supplier supplier = cmbSupplier.SelectedItem as Supplier;

            CategoryBindingSource.DataSource = category;
            SupplierBindingSource.DataSource = supplier;
            //TODO - Get products for this supplier and category

            using (var db = new NORTHWNDEntities())
            {
                var query = from p in db.Products
                            where p.Category.CategoryID == category.CategoryID && p.Supplier.SupplierID == supplier.SupplierID
                            select p;

                List <Product> allproducts = query.ToList();
                ProductBindingSource.DataSource = allproducts;
            }

            //TODO - Send all data to the report and show the report

            this.reportViewer1.RefreshReport();
        }