我的xaml页面

public About()
        {
            InitializeComponent();

            this.Title = ApplicationStrings.AboutPageTitle;


            EntityQuery<Web.Models.Class1> qry = context.GetProductSummaryListQuery();
            //page 167
            qry = qry.OrderBy(p => p.Name);
            //the following is asynchronous, therefore any immediate WORKING ON RESULT
            //must be done in the oparation.completed event
            LoadOperation<Web.Models.Class1> operation = context.Load(qry);
            dataGrid1.ItemsSource = operation.Entities;



            //context.Class1s.
           // bool changes_there = context.HasChanges;
        }

我的班级

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;


namespace Tutorial1.Web.Models
{
    public partial class Class1
    {

        [Key]
        [Editable(false)]
        public int ID { get; set; }
        public string Name { get; set; }
        public string Number { get; set; }
        public decimal ListPrice { get; set; }
        public byte[] ThumbNailPhoto { get; set; }
        public int? QuantityAvailable { get; set; }
        public string Category { get; set; }
        public string SubCategory { get; set; }
        public string Model { get; set; }
        public bool MakeFlag { get; set; }
    }

}

我的服务

namespace Tutorial1.Web.Services
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.ComponentModel.DataAnnotations;
    using System.Linq;
    using System.ServiceModel.DomainServices.Hosting;
    using System.ServiceModel.DomainServices.Server;
    using Tutorial1.Web.Models;

    // TODO: Create methods containing your application logic.
    [EnableClientAccess()]
    public class ProductPMService : DomainService
    {
        private AdventureWorksLTEntities context = new AdventureWorksLTEntities();

        public IQueryable<Web.Models.Class1> GetProductSummaryList()
        {
            return from p in this.context.Products
                   select new Web.Models.Class1()
                   {
                       ID = p.ProductID,
                       ListPrice = p.ListPrice,
                       Name=p.Name
                   };

        }



        public IQueryable<ProductPM> GetProductsFromDB()
        {
            return from p in context.Products
                   select new ProductPM()
                   {
                       ProductID = p.ProductID,
                       Name = p.Name,
                       ProductNumber = p.ProductNumber,
                       ListPrice = p.ListPrice,
                       ModifiedDate = p.ModifiedDate
                   };

        }//get products

        public void InsertProductToDB(ProductPM the_class)
        {
            Product product = new Product();
            product.Name = the_class.Name;
            product.ProductNumber = the_class.ProductNumber;
            product.ListPrice = the_class.ListPrice;
            product.ModifiedDate = DateTime.Now;


            //concurrency
            //ProductPM originalproduct = ChangeSet.GetOriginal<ProductPM>(the_class);


            context.Products.AddObject(product);
            context.SaveChanges();

            ChangeSet.Associate(the_class, product, UpdateProductPMKeys);
        }//InsertProduct

        private void UpdateProductPMKeys(ProductPM the_class, Product product)
        {//reflecting the generated id back.
            the_class.ProductID = product.ProductID;
            the_class.ModifiedDate = product.ModifiedDate;
        }//reflecting the generated id back ends


        protected override void OnError(DomainServiceErrorInfo errorInfo)
        {
            // Log exception here
                    }

    }
}

我不明白什么是绑定源，在按钮点击时我应该添加一行。

Answer 1

我在您的代码中看到了两个问题。

1）在xaml页面后面的代码中，将加载操作的结果分配给datagrid的ItemsSource。

dataGrid1.ItemsSource = operation.Entities;

问题在于operation.Entities属于IEnumerable<TEntity>类型，因此没有Add-method。我建议定义一个ObservableCollection并将其用作ItemsSource，并在Load-operation的回调方法中填充operation.Entities的内容。也许你可以使用这样的东西（简化版，未经测试）：

public ObservableCollection<Web.Models.Class1> Class1Collection { get; set; }

context.Load<T>(qry, r =>
{
  if (r.HasError)
  {
    // error handling
  }
  else if (r.Entities.Count() > 0)
  {
    this.Class1Collection.Clear();
    foreach (Web.Models.Class1 c in r.Entities)
    {
      this.Class1Collection.Add(c);
    }
  }
  else 
  {
    // handle case when no Entities were returned
  }
}, null);

在构造函数中使用：

dataGrid1.ItemsSource = this.Class1Collection;

如果您这样做，可以使用以下方法添加新项目：

Web.Models.Class1 newItem = new Web.Models.Class1();
this.Class1Collection.Add(newItem);
context.GetEntitySet<Web.ModelsClass1>().Add(newItem);

2）您没有在DomainService中为Class1定义Insert或Update方法。我对你使用Class1和ProductPM感到有些困惑。它们应该是一样的吗？

无论如何，如果你想添加Class1的新实例，你需要在DomainService中使用InsertClass1(Class1 newObject)方法（最好也是Update方法）。

如何识别数据源以将行添加到数据源绑定到datagrid Silverlight？

我的xaml页面

我的班级

我的服务

1 个答案: