add attribute other than value to DropDownList items when using SqlDataSource

Question

I have a DropDownList bound to a SqlDataSource as follows:

<asp:DropDownList ID="ddlist" AppendDataBoundItems="True" DataSourceID="SqlDataSource1" DataTextField="name" DataValueField="value" AutoPostBack="True" runat="server">
    <asp:ListItem></asp:ListItem>
</asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSource1" ConnectionString="<%$ ConnectionStrings:myConnectionString %>" SelectCommand="SELECT [name], [value] FROM [myTable]" runat="server"></asp:SqlDataSource>

I would like to bind a third database column to another attribute (not value), say database table column DefaultBit to ListItem attribute data-default so that the DropDownList renders as

<select>
    <option></option>
    <option value="1" data-default="1">Line 1</option>
    <option value="2" data-default="0">Line 2</option>
</select>

I assume I need to do this programmatically in the code-behind file, but it's not clear to me if I would still bind a SqlDataSource to the DropDownList or if I should open a connection and iterate through the results using SqlReader and update the DropDownList "manually" or some other more elegant solution.

http://stackoverflow.com/questions/11834920/how-to-add-a-data-attribute-to-a-dropdown-menu-with-c-sharp — laskdjf, Jun 11 '15 at 18:00

score 2 · Accepted Answer · edited Jul 30 '17 at 14:00

Please try following solution:

Add DropDownList and SqlDataSource mark up as (please note I have added OnDataBound="ddlist_DataBound" and third column in select statement)

<asp:DropDownList ID="ddlist" AppendDataBoundItems="True" OnDataBound="ddlist_DataBound"
  DataSourceID="SqlDataSource1" DataTextField="name" DataValueField="value"
  AutoPostBack="True" runat="server">
    <asp:ListItem></asp:ListItem>
</asp:DropDownList>

<asp:SqlDataSource ID="SqlDataSource1" ConnectionString=
   "<%$ ConnectionStrings:myConnectionString %>" SelectCommand="SELECT [name], [value],
   [DefaultBit] FROM [myTable]" runat="server">
</asp:SqlDataSource>

Add code behind method "ddlist_DataBound" as:(please note row[0] is name, row[1] is value and row[2] is DefaultBit)

protected void ddlist_DataBound(object sender, EventArgs e) {
    System.Data.DataTable dt = new System.Data.DataTable();
    System.Data.DataView dv = (System.Data.DataView)SqlDataSource1.Select(DataSourceSelectArguments.Empty);
    dt = dv.ToTable();

    foreach (System.Data.DataRow row in dt.Rows) {
        ddlist.Items.FindByValue(row[1].ToString()).Attributes.Add("data-default", row[2].ToString());
    }
}

I have tested it in an application and works beautifully.

I came to the same solution independently, so your answer gives me more confidence that this is the way to go. I found; however, that running the code behind method onDataBound resulted in the attribute not surviving postbacks. Instead I used onPreRender so that the attributes were added on every postback. — Chris Purves, Jun 16 '15 at 15:34

add attribute other than value to DropDownList items when using SqlDataSource

1 Answers1