HiddenEmailAttachment Custom Field Type

HiddenEmailAttachment.cs

namespace ISlayTitans.Cms.WebForms.Fields
{
    public class HiddenEmailAttachment : Sitecore.Form.Web.UI.Controls.List
    {
        protected override void OnInit(EventArgs e)
        {
            base.OnInit(e);
 
            this.Attributes.Add("style", "display:none;");
 
            // The chosen values can be accessed via the SelectedValue property
            var mediaItemIds = SelectedValue;
        }
    }
}