GridView、Repeater合并单元格可以参考http://www.cnblogs.com/zhmore/archive/2009/04/22/1440979.html，但是原文例子是合并一列的单元格。
现在有2列需要分别合并单元格，如下所示，“类型”和“操作”当有相同的值时要分别合并：
可以在原来的代码上稍做改动，前台代码如下：
<asp:Repeater runat="server" ID="rptList">
<HeaderTemplate>
<table width="100%" border="1" cellpadding="4" cellspacing="0" bgcolor="#464646" style="border-collapse:collapse; padding:0; margin:0">
<tr bgcolor="#eeeeee">
<td>序号</td>
<td>类型</td>
<td>操作</td>
<td>编号</td>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr bgcolor="#ffffff">
<td><%# Eval("rn") %></td>
<td runat="server" id="td1"><%#Eval("Col1")%></td>
<td runat="server" id="td2"><%#Eval("Col2")%></td>
<td><%#Eval("Col3")%></td>
<td><%#Eval("Col4")%></td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
后台代码如下：
private void BindData()
{
rptList.DataSource = null; //这里为数据源，省略...
rptList.DataBind();
MergeCell("td1", "td2");
}
private void MergeCell(string tdIdName1, string tdIdName2)
{
for (int i = rptList.Items.Count - 1; i > 0; i--)
{
MergeCellSet(tdIdName1, tdIdName2, i);
}
}
private void MergeCellSet(string tdIdName1, string tdIdName2, int i)
{
HtmlTableCell cellPrev = rptList.Items[i - 1].FindControl(tdIdName1) as HtmlTableCell;
HtmlTableCell cell = rptList.Items[i].FindControl(tdIdName1) as HtmlTableCell;
cell.RowSpan = (cell.RowSpan == -1) ? 1 : cell.RowSpan;
cellPrev.RowSpan = (cellPrev.RowSpan == -1) ? 1 : cellPrev.RowSpan;
if (cell.InnerText == cellPrev.InnerText)
{
cell.Visible = false;
cellPrev.RowSpan += cell.RowSpan; //关键代码，再判断执行第2列的合并单元格方法
if (tdIdName2 != "") MergeCellSet(tdIdName2, "", i);
}
}