数据绑定列表与子相关的内容最好的方式（例如，SO的问题与标签） [英] Best Way to DataBind a List with sub-related content (For example, SO's questions with tags)

问题描述

使用ASP.net 2.0，我怎么present的信息，类似上那么，每个问题有一定的子项（如标签）的问题清单用户。

Using ASP.net 2.0, how do I present the information to the user similar to the Questions list on SO where each question has some child items (like the tags).

我很可能会使得两个单独的查询，一是先找到问题的列表，然后另一个查询发现其中区属的问题列表中的所有标签。

I would probably be making two separate queries, one to first find the list of questions, then another query to find all tags which belonged to the list of questions.

方法1：

然后，我很可能会使用嵌套的中继器和做在$ C $每个嵌套Repeater C-后面的select语句OnItemDataBind...

Then I would probably be using nested repeaters and doing a select statement in the code-behind on each nested repeater "OnItemDataBind"...

方法二：

或者用两个数据集，我会用C＃code创建每个问的公司实体，有一个名为标签属性。然后我会遍历我的标签数据和分配财产。

Or with the two datasets, I would use C# code to create a business entity of each of the "Questions" and have a property called "Tags". I would then loop through my tags dataset and assign the property.

请告诉我更有效率？是否有任何其他的选择吗？

Whats more efficient? Is there any other alternatives?

推荐答案

我肯定会避免第二种方法 - 你不想打你一个数据绑定父项目数据库每次。作为DOK说，尽量妥善建筑师您的系统。对我来说，这将意味着填充业务对象的集合，并绑定到它。我做一个自定义菜单控件（注意，这个巢3 datalists，但你可以使用中继器）类似的东西：

I would definitely avoid the second approach - you don't want to hit the database everytime you databind a parent item. As DOK says, try and architect your system properly. For me that would mean populating a collection of business objects and binding to it. I do something similar with a custom menu control (note this nests three datalists, but you could use repeaters):

在aspx页面：

<asp:DataList ID="dlMenuOne" runat="server" onitemdatabound="dlMenu_ItemDataBound" >
            <ItemTemplate>
             //your object

                <asp:DataList ID="dlMenuTwo"  runat="server" onitemdatabound="dlMenuTwo_ItemDataBound">
                <ItemTemplate>
                //your object's child items

                    <asp:DataList ID="dlMenuThree" runat="server">
                    <ItemTemplate>
                       //child item's child items    
                    </ItemTemplate>
                    </asp:DataList>

                </ItemTemplate>
                </asp:DataList> 

            </ItemTemplate>
            </asp:DataList>

然后在code背后：

then in the code behind:

protected void dlMenu_ItemDataBound(object sender, DataListItemEventArgs e)
{
    DataListItem parentList = e.Item;
    DataList dlMenuTwo = (DataList)parentList.FindControl("dlMenuTwo");
    MenuItem item = (MenuItem)parentList.DataItem;
    dlMenuTwo.DataSource = _menu.GetChildItems(item);
    dlMenuTwo.DataBind();
}

这种方法基本上是获取对对象的引用绑定（parentList.DataItem），然后结合嵌套DataList控件的子项（_menu.GetChildItems（项目））

this method basically gets a reference to the object being bound (parentList.DataItem) and then binds the nested DataList to the child items (_menu.GetChildItems(item))

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