The following code block below will allow you to display spacing or indention in the DropDownList items.

protected void Page_Load(object sender, EventArgs e){

        if (!Page.IsPostBack)
        {
            const string spaceChar = "    ";
            DropDownList1.Items.Add(new ListItem("Parent Item 1", "Parent Item 1"));
            DropDownList1.Items.Add(new ListItem("Parent Item 2", "Parent Item 2"));
            DropDownList1.Items.Add(new ListItem(Server.HtmlDecode(spaceChar + "Sub1 Item 2"), "Sub1 Item 2"));
            DropDownList1.Items.Add(new ListItem(Server.HtmlDecode(spaceChar + "Sub2 Item 2"), "Sub2 Item 2"));
            DropDownList1.Items.Add(new ListItem(Server.HtmlDecode(spaceChar + spaceChar + "Sub1 Item 3"), "Sub1 Item 3"));
            DropDownList1.Items.Add(new ListItem("Parent Item 3", "Parent Item 3"));
        }
}

As you can see we just Decode the character    the HTML equivalent for Space and then append it to the actual ListItems of the DropDownList..

See the sample output below:



That's it! Hope you will find this example useful!

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