Question

I want to set first option value to 0 instead leaving it blank. How can I set this?
i.e

<select id="PatentId" name="ParentId">
     <option value="0">--Select--</option>
     <option value="1">Books</option>
      // other options
</select>

My code is as

<div class="editor-field">
     @Html.DropDownList("ParentId","--Select--")
     @Html.ValidationMessageFor(model => model.ParentId)
</div>

Answer 1

Finally I found the following code working

private SelectList AddFirstItem(SelectList list)
{
   List<SelectListItem> _list = list.ToList();
   _list.Insert(0, new SelectListItem() { Value = "0", Text = "--Select--" });
   return new SelectList((IEnumerable<SelectListItem>)_list, "Value", "Text", list.SelectedValue);
}

Keep the “Value” and “Text”. The Last one list.SelectedValue is to keep selected values as it is.

You can use the above function like

public ActionResult Create()
{
    ViewBag.ParentId = AddFirstItem(new SelectList(db.Categories, "Id", "Name"));
    return View();
} 

It worked.