populating drop down value and item based on the selection of first drop down asp.net

Question

It is a common question and I took hint from these two links too. Dropdown list items based on value of another drop down list

load a drop down box based on selected option in first drop down box

But none of them has provided complete solutions. I need to populate both the items along with their values.

aspx code ::

<asp:DropDownList ID="ddlFirstSelection" runat="server" AutoPostBack="true" 
    OnSelectedIndexChanged="ddlFirstSelection_SelectedIndexChanged">
    <asp:ListItem Value="0">select</asp:ListItem>
    <asp:ListItem Value="1">new record</asp:ListItem>
    <asp:ListItem Value="2">old record</asp:ListItem>
</asp:DropDownList>
 <%----- second drop down to be populated from code behind based on ddlFirstSelection selection ------%>
<asp:DropDownList ID="ddlPlan" runat="server"></asp:DropDownList>

code behind ::

protected void ddlFirstSelection_SelectedIndexChanged(object sender, EventArgs e)
        {
                if(ddlFirstSelection.SelectedValue=="1")
                {
                    ddlPlan.Items.Clear();                    
                    ddlPlan.DataTextField = "ground floor";
                    ddlPlan.DataValueField = "1";
                    ddlPlan.DataTextField = "first floor";
                    ddlPlan.DataValueField = "2";
                    ddlPlan.DataBind();
                }

        }

How to create a List to populate the ddlPlan drop down? Is there any other way rather than creating datatable for this?

Answer 1

You can simply create List of AnonymousType object and bind that to the DataSource of second DropDownList.

            //create list of anonymoustype
            var list = new[] 
            {
                new { Id = 1, Name = "ground floor" },
                new { Id = 2, Name = "first floor" },
            }.ToList();

            ddlPlan.Items.Clear();

            ddlPlan.DataTextField = "Name";
            ddlPlan.DataValueField = "Id";

            //bind anonymous type list to DataSource
            ddlPlan.DataSource = list;
            ddlPlan.DataBind();