C# 使用自定义实体数据绑定的排序问题

使用自定义实体类对Gridview进行排序时出现问题

我的复杂实体

public class Subscription
{

    public string SubscriptionID { get; set; }
    public string Status { get; set; }
    public Customer { get; set; } //Contained class from another entity
}


public class Customer
{
    public string CustomerID { get; set; }
    public CustomerName { get; set; }
}

绑定到gridview

 List<Subscription> subscriptions = GetSubscriptions();


 //sorting, sortEvent is the GridviewSortEvenArgs param
 subscriptions.Sort(new GenericComparer<Subscription>(sortEvent.SortExpression, GridViewSortDirection));



 grdSubscription.DataSource = subscriptions;
 grdSubscription.DataBind();

---

请提前告知，谢谢

您可以尝试的一个快速而肮脏的方法是将CustomerName属性添加到您的Subscription类中。在使用Silverlight/WCF/EF时，我通常在客户端代码分部类中这样做

public string CustomerName 
{ get 
   { return Customer != null ? Customer.CustomerName : string.empty }
}

---

然后从您的UI引用此属性。

如何绑定排序？是的，我可以简单地添加此属性，但它将提升redunduncy，因为我的Customer类中已经有CustomerName。。。我将实体设计为实际数据库的规范化表。。谢谢当我想消除我的数据问题在哪里的问题时，我会使用这个。例如，在EF中，有时订阅对象没有深度加载，例如，除非.IncludeCustomer在查询方法中，否则不会创建Customer实例。解决这些问题后，您可以删除冗余属性，尽管Subscription类的用户可能会喜欢helper方法，而不必总是对Subscription.Customer.CustomerName进行编码

     <asp:TemplateField HeaderText="Subscription ID" SortExpression="SubscriptionID">

       <asp:TemplateField HeaderText="Customer Name" SortExpression="CustomerName">
                <ItemTemplate>
                   <%# Eval(" Customer.CustomerName ") %>
                </ItemTemplate>

   public class GenericComparer<T> : IComparer<T>
{
    private SortDirection sortDirection;

    public SortDirection SortDirection
    {
        get { return this.sortDirection; }
        set { this.sortDirection = value; }

    }

    private string sortExpression;

    public GenericComparer(string sortExpression, SortDirection sortDirection)
    {
        this.sortExpression = sortExpression;
        this.sortDirection = sortDirection;
    }

    public int Compare(T x, T y)
    {
        PropertyInfo propertyInfo = typeof(T).GetProperty(sortExpression);

        IComparable obj1 = (IComparable)propertyInfo.GetValue(x, null);
        IComparable obj2 = (IComparable)propertyInfo.GetValue(y, null);

        if (SortDirection == SortDirection.Ascending)
        {
            return obj1.CompareTo(obj2);
        }

        else return obj2.CompareTo(obj1);
    }
}

     protected SortDirection GridViewSortDirection
{
    get
    {
        // Checks for the first time when the ViewState sort direction is null
        if (ViewState["sortDirection"] == null)
            ViewState["sortDirection"] = SortDirection.Ascending;
        // Changes the sort direction
        else
        {
            if (((SortDirection)ViewState["sortDirection"]) == SortDirection.Ascending)
            {
                ViewState["sortDirection"] = SortDirection.Descending;
            }
            else
            {
                ViewState["sortDirection"] = SortDirection.Ascending;
            }
        }
        return (SortDirection)ViewState["sortDirection"];
    }
    set
    {
        ViewState["sortDirection"] = value;

    }
}

public string CustomerName 
{ get 
   { return Customer != null ? Customer.CustomerName : string.empty }
}