如何使用LINQ xamarin.forms连接两个表

Question

我正在将xamarin表单与ORM EF配合使用，我想在数据gridView中显示product和salesOrderItems中的数据。我的问题是网格是空的。这里是我的代码。

public SalesOrderDetailsVM(int salesOrderItemId)
    {
        _salesOrderItemId = salesOrderItemId;
        _context = new DatabaseContext();
        var salesOrderItem = _context.SalesOrderItems.Find(salesOrderItemId);
        var idsalesOrder = salesOrderItem.SalesOrderId;
        var salesOrder = _context.SalesOrders.Find(idsalesOrder);
        var idProd = salesOrderItem.ProductId;
        _context = new DatabaseContext();
        var Customer = _context.Customers.Where(t => t.CustomerId == salesOrder.CustomerId).FirstOrDefault();
        // Setting property values from customer and salesOrder object
        // that we get from database
        DateCreation = salesOrder.DateCreation;
        NumBc = salesOrder.NumBc;
        CustomerName = Customer.MangerFullName;
        CustomerCIN = Customer.CIN;
        var Products = (from p in _context.Products
                         join o in _context.SalesOrderItems
                         on p.ProductId equals o.ProductId

                         select new 
                         {
                             Code = p.Code,
                             Designation = p.Designation,
                             Order_Qty = o.Order_Qty,
                             PrixUnitaire = p.PrixUnitaire,
                             TotalHt = o.TotalHt

                         }).ToList();   }

Answer 1

itemCount