Question

我在使用自定义实体类

排序Gridview时遇到问题

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();

我使用模板字段将我的实体字段绑定到网格

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

现在在排序中，它在排序Subscription的Native属性

时工作正常

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

但是我在排序所包含的类（Customer）

的属性方面遇到了问题

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

我尝试过SortExpression =“Customer.CustomerName”，但无济于事

我使用这个GenericComparer来排序网格

   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);
    }
}

其他详细信息：

     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;

    }
}

请提前告知

Answer 1

您可以尝试的一个快速而肮脏的事情是将CustomerName属性添加到Subscription类。我通常在使用Silverlight / WCF / EF时在客户端代码分部类中执行此操作。

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

然后从您的UI中引用此属性。

使用自定义实体数据绑定排序问题

1 个答案: