c# - 如何将 GridView 绑定(bind)到复杂对象

Question

public class BE_RoomRateService
{
    public IQueryable<RoomRateWithRoomType> RoomRateForAdmin()
    {
                var query= from rate in db.BE_RoomRates 
                           join room in db.BE_Rooms
                           on rate.RoomId equals room.RoomId
                           where rate.Status!=3 && room.Status!=3
                           select new RoomRateWithRoomType()
                           {
                               RoomRate = rate,
                               RoomType = room.RoomType

                           };
                return query;
     }
}

public class RoomRateWithRoomType
{
            public BE_RoomRate RoomRate { get; set; }
            public string RoomType { get; set; }
}

这里 RoomRateForAdmin 现在返回 RoomRateWithRoomType 的集合，当我想使用此代码将我的网格与此方法结果绑定(bind)时。

grdData.DataSource = bs.RoomRateForAdmin();
grdData.DataBind();

然后它给我错误:
BussinessLogic.Data.RoomRateWithRoomType' 不包含名为“SingleRate”的属性。

因为我的 GridView aspx 页面如下:

<asp:GridView ID="grdData" runat="server" AutoGenerateColumns="false" GridLines="None"
Width="900" OnRowDataBound="grdData_RowDataBound" OnRowCommand="grdData_RowCommand" >
    <Columns>
        <asp:TemplateField>
            <HeaderTemplate>
                Room Type</HeaderTemplate>
            <ItemTemplate>
                <asp:Label ID="lblRoomType" runat="server" Text='<%# Eval("RoomType")%>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField>
            <HeaderTemplate>
                Single Rate</HeaderTemplate>
            <ItemTemplate>
                <asp:Label ID="lblSingleRate" runat="server" Text='<%# Eval("SingleRate")%>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
            <asp:TemplateField>
            <HeaderTemplate>
                Double Rate</HeaderTemplate>
            <ItemTemplate>
                <asp:Label ID="lblDoubleRate" runat="server" Text='<%# Eval("DoubleRate")%>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField>
            <HeaderTemplate>
                Start Date</HeaderTemplate>
            <ItemTemplate>
                <asp:Label ID="lblStartDate" runat="server" Text='<%# Eval("StartDate")%>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField>
            <HeaderTemplate>
                End Date</HeaderTemplate>
            <ItemTemplate>
                <asp:Label ID="lblEndDate" runat="server" Text='<%# Eval("EndDate")%>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
            <asp:TemplateField>
            <HeaderTemplate>
                Status</HeaderTemplate>
            <ItemTemplate>
                    <asp:ImageButton ID="imgStatus" runat="server" CommandName="Status" />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField>
            <HeaderTemplate>
                Edit</HeaderTemplate>
            <ItemTemplate>
                <asp:ImageButton ID="imgEdit" runat="server" ToolTip="Click here to view/edit this Events"
                    AlternateText="Edit" CommandName="EditRow" CommandArgument='<%# Bind("RoomRateId") %>' />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField>
            <HeaderTemplate>
                Delete</HeaderTemplate>
            <ItemTemplate>
                <asp:ImageButton ID="imgDelete" runat="server" ToolTip="Click here to delete this Events"
                    AlternateText="Delete" CommandName="Del" CommandArgument='<%# Bind("RoomRateId") %>' />
            </ItemTemplate>
        </asp:TemplateField>

    </Columns>
</asp:GridView>

我知道我无法直接获取 RoomRate 表属性，但我不知道如何获取 BE_RoomRate 类的属性。

我的问题可能看起来非常大，因为我不知道如何直接提问，所以任何人都会编辑这个问题以在小版本中表达我的观点。

Answer 1

如果你想获得 RoomRate SingleRate。然后而不是使用

Eval("SingleRate")

使用

DataBinder.Eval(Container.DataItem, "RoomRate.SingleRate")

看这个小例子(代码隐藏)

public class SomeObject
{
    public Version Version { get; set; }
    public string Description { get; set; }
}
protected void Page_Load(object sender, EventArgs e)
{
    var ls = new List<SomeObject>()
                            {
                                new SomeObject() {Description = "Test", Version = new Version(1, 1)},
                                new SomeObject() {Description = "Test2", Version = new Version(2, 1)}
                            };
    gv.DataSource = ls;
    gv.DataBind();
}

aspx:

<asp:GridView ID="gv" runat="server" Width="100%">
        <Columns>
            <asp:TemplateField>
            <HeaderTemplate>
                Major</HeaderTemplate>
            <ItemTemplate>
                <asp:Label ID="lblRoomType" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "Version.Major") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        </Columns>
    </asp:GridView>

因为 DataKeyNames 属性是一个字符串而不是一个表达式，所以我建议您为此创建一个属性。所以你的对象看起来像这样:

public class RoomRateWithRoomType
{
      public BE_RoomRate RoomRate { get; set; }
      public string RoomType { get; set; }
      public int RoomRateId { get; set; }
}

然后在网格中你可以使用:

DataKeyNames="RoomRateId"

为避免每行一次数据库调用，请更改此设置:

public IQueryable<RoomRateWithRoomType> RoomRateForAdmin()
{
            var query= from rate in db.BE_RoomRates 
                       join room in db.BE_Rooms
                       on rate.RoomId equals room.RoomId
                       where rate.Status!=3 && room.Status!=3
                       select new RoomRateWithRoomType()
                       {
                           RoomRate = rate,
                           RoomType = room.RoomType

                       };
            return query;
 }

到

public IEnumerable<RoomRateWithRoomType> RoomRateForAdmin()
        {
                    var query= from rate in db.BE_RoomRates 
                               join room in db.BE_Rooms
                               on rate.RoomId equals room.RoomId
                               where rate.Status!=3 && room.Status!=3
                               select new RoomRateWithRoomType()
                               {
                                   RoomRate = rate,
                                   RoomType = room.RoomType

                               };
                    return query.ToList();
         }