List of strings get one item distinct

Question

i have bind list to repeater (asp.net)

it shows like this

i want to bind like this

My Code

<asp:Repeater ID="RptID" runat="server">
    <ItemTemplate>
        <tr>
            <td><%# Eval("T") %> :</td>
            <td><%# Eval("D") %> :</td>
        </tr>
    </ItemTemplate>
</asp:Repeater>

C#

List<Options> pList = List Type of options;
RptID.DataSource = pList;
RptID.DataBind();

Data Source

public class Options
{
    public string T { get; set; }
    public string D { get; set; }
}

How to do this?

Answer 1

You have to add the ItemDataBound event to the Repeater first. Then add a ternary operator that will evaluate the global string previousValue, that has the previous value of T.

<asp:Repeater ID="RptID" runat="server" OnItemDataBound="RptID_ItemDataBound">
    <ItemTemplate>
        <tr>
            <td><%# previousValue != Eval("T").ToString() ? Eval("T") + ":" : "" %></td>
            <td><%# Eval("D") %></td>
        </tr>
    </ItemTemplate>
</asp:Repeater>

Then in code behind add the OntItemDataBound method and the global variable.

public string previousValue = "";

protected void RptID_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    //cast the item back to a datarowview
    DataRowView item = e.Item.DataItem as DataRowView;

    //assign the new value to the global string
    previousValue = item["T"].ToString();
}

Or if you bind a List<class>, you need to do this:

protected void RptID_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    //cast the item back to its class
    Options item = e.Item.DataItem as Options;

    //assign the new value to the global string
    previousValue = item.T;
}