添加项目文件。

XXCpzs/ViewModels/SaleViewModel.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Text;
+using Xamarin.Forms;
+using XXCpzs.Models;
+using XXCpzs.Views;
+
+namespace XXCpzs.ViewModels
+{
+    class SaleViewModel : BaseViewModel
+    {
+        public ObservableCollection<ResultModel> Items { set; get; }
+        string companyName = string.Empty;
+        public string CompanyName
+        {
+            get { return companyName; }
+            set { SetProperty(ref companyName, value); }
+        }
+
+        public int CustomerId = 0;
+
+        public SaleViewModel()
+        {
+            Title = "产品销售";
+            Items = new ObservableCollection<ResultModel>
+            {
+                new ResultModel { Data = "序列号", Msg = "提交结果" }
+            };
+            MessagingCenter.Subscribe<PageCustomerSelect, Customer>(this, "SelectCustomer", async (obj, item) =>
+            {
+                var newItem = item as Customer;
+                this.CompanyName = newItem.company + ">>" + newItem.contacts;
+                this.CustomerId = newItem.id;
+            });
+        }
+    }
+}