private async void BtnAddDelivery_Click(object sender, EventArgs e) { var delivery = new Delivery() { DeliveryDate = DateTime.Now, ReferenceNum = Guid.NewGuid().ToString(), Description = "Delivery 1", TotalWeight = 110, Splits = new List <Split>() { new Split() { Id = Guid.NewGuid().ToString(), Description = "Split 1", Quantity = 10, Weight = 50, GarmentCount = 1000, Steps = new List <Step>() { new Step() { Id = Guid.NewGuid().ToString(), Date = DateTime.Now.Date, Location = "Ho Chi Minh" }, new Step() { Id = Guid.NewGuid().ToString(), Date = DateTime.Now.Date, Location = "Ha Noi" } } }, new Split() { Id = Guid.NewGuid().ToString(), Description = "Split 2", Quantity = 20, Weight = 80, GarmentCount = 2000, Steps = new List <Step>() { new Step() { Id = Guid.NewGuid().ToString(), Date = DateTime.Now.Date, Location = "Da Nang" }, new Step() { Id = Guid.NewGuid().ToString(), Date = DateTime.Now.Date, Location = "Can Tho" } } }, } }; var deliveryService = new DeliveryService(); var result = await deliveryService.AddDeliveryAsync(delivery); }