C#中绑定Repeater控件出现重复数据问题求助

使用Repeater控件尝试分组展示数据，但出现重复内容。当前显示效果：

存储过程返回的数据库数据：

已尝试将内容移到HeaderTemplate、绑定到列表等方法，问题仍未解决，寻求帮助。

Repeater控件代码 #

<asp:Repeater ID="GroupRepeater" OnItemDataBound="GroupRepeater_ItemDataBound" runat="server">
    <HeaderTemplate>
        <asp:HiddenField ID="CompanyName" runat="server" />
           
    </HeaderTemplate>
    <ItemTemplate>     
        <div id="BoardGrpName">
            <%# Eval("BoardGroupName") %>
        </div> 
        <div id="BoardCompanyName1">
            <%# Eval("CompanyName") %>
        </div>
        <div id="BoardCompanyName2">
            <%# Eval("BoardMemberName") %>
        </div>
        <br />
    </ItemTemplate>
    <FooterTemplate>
        <div class="label label-light" id="BoardMemberName">                                       
            <asp:Label ForeColor="Black" Font-Size="12px" runat="server"><%# Eval("BoardMemberName") %></asp:Label>                                                                                       
        </div>               
    </FooterTemplate>
</asp:Repeater>   

后台代码（Code Behind） #

protected void Page_Load(object sender, EventArgs e)
{
    try
    {
        if (!Page.IsPostBack)
        {
            //load board members                    
            GroupRepeater.DataSource = DbHelper.SqlStoredProcedureDataTable("spQueryFullBoardInfo", ConfigurationManager.ConnectionStrings["NConnectionString"].ConnectionString);
            GroupRepeater.DataBind();
            divMessage.Visible = false;                   
        }
    }
    catch (Exception ex)
    {
       catch error here
    }           
}

Repeater本身无原生分组功能，当前重复显示是因为每条数据都渲染了BoardGroupName和CompanyName。以下两种方法可实现分组效果：

方法1：后台分组后绑定嵌套Repeater #

先在后台对数据按分组字段聚合，再通过嵌套Repeater展示分组标题和下属成员。

1. 定义分组模型

public class BoardGroup
{
    public string BoardGroupName { get; set; }
    public string CompanyName { get; set; }
    public List<string> BoardMemberNames { get; set; }
}

2. 修改后台数据绑定逻辑

protected void Page_Load(object sender, EventArgs e)
{
    try
    {
        if (!Page.IsPostBack)
        {
            DataTable dt = DbHelper.SqlStoredProcedureDataTable("spQueryFullBoardInfo", ConfigurationManager.ConnectionStrings["NConnectionString"].ConnectionString);
            // 按BoardGroupName+CompanyName分组
            var groupedData = dt.AsEnumerable()
                                .GroupBy(row => new 
                                { 
                                    GroupName = row.Field<string>("BoardGroupName"),
                                    CompanyName = row.Field<string>("CompanyName")
                                })
                                .Select(g => new BoardGroup
                                {
                                    BoardGroupName = g.Key.GroupName,
                                    CompanyName = g.Key.CompanyName,
                                    BoardMemberNames = g.Select(row => row.Field<string>("BoardMemberName")).ToList()
                                })
                                .ToList();
            GroupRepeater.DataSource = groupedData;
            GroupRepeater.DataBind();
            divMessage.Visible = false;                   
        }
    }
    catch (Exception ex)
    {
        // 异常处理逻辑
    }           
}

3. 修改Repeater为嵌套结构

<asp:Repeater ID="GroupRepeater" runat="server">
    <ItemTemplate>     
        <div id="BoardGrpName">
            <%# Eval("BoardGroupName") %>
        </div> 
        <div id="BoardCompanyName1">
            <%# Eval("CompanyName") %>
        </div>
        <!-- 嵌套Repeater展示成员列表 -->
        <asp:Repeater ID="MemberRepeater" runat="server" DataSource='<%# Eval("BoardMemberNames") %>'>
            <ItemTemplate>
                <div id="BoardCompanyName2">
                    <%# Container.DataItem %>
                </div>
            </ItemTemplate>
        </asp:Repeater>
        <br />
    </ItemTemplate>
</asp:Repeater>   

方法2：在ItemDataBound中控制分组标题显示 #

通过记录上一条数据的分组信息，判断当前项是否需要显示分组标题（需确保数据源已按分组字段排序）。

1. 添加页面级变量记录上一分组

private string _lastGroupName = string.Empty;
private string _lastCompanyName = string.Empty;

2. 实现ItemDataBound事件

protected void GroupRepeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        DataRowView row = (DataRowView)e.Item.DataItem;
        string currentGroupName = row["BoardGroupName"].ToString();
        string currentCompanyName = row["CompanyName"].ToString();

        // 获取分组标题控件
        Control groupNameDiv = e.Item.FindControl("BoardGrpName");
        Control companyNameDiv = e.Item.FindControl("BoardCompanyName1");

        // 与上一分组相同则隐藏标题
        if (currentGroupName == _lastGroupName && currentCompanyName == _lastCompanyName)
        {
            groupNameDiv.Visible = false;
            companyNameDiv.Visible = false;
        }
        else
        {
            // 更新记录的分组信息
            _lastGroupName = currentGroupName;
            _lastCompanyName = currentCompanyName;
        }
    }
}

注意：需在存储过程中添加ORDER BY BoardGroupName, CompanyName，确保数据按分组字段排序，否则分组会混乱。

内容的提问来源于stack exchange，提问作者DotNetter