MVC3 Dropdownlist - String / Role Value

Ok here is my challenge: I want to create a dropdownlist with three strings in my Register View - "Please Select", "I am a client", and "I am a vendor". When the user selects the "I am a client" and submits he is added to the "Client" role. When the user selects the "I am a Vendor" role he is added to the "Vendor" role. If the user doesn't select either and leaves on "Please select" validation occurs.

I can get the roles to directly populate via the ViewBag. Here's how:

Register.cshtml -

        <div class="editor-label">
            @Html.LabelFor(m => m.Role, "I am a:")
        </div>
        <div class="editor-field">
            @Html.DropDownList("Role", ViewBag.Roles as SelectList,"Please Select")
        </div>

AccountModel.cs -

public class RegisterModel
{

    [Required]
    [Display(Name = "Role")]
    public string Role { get; set; }

AccountController.cs -

    public ActionResult Register()
    {

        ViewBag.Roles = new SelectList(Roles.GetAllRoles().ToList());
        return View();

What I still need to accomplish - Currently the dropdownlist only populates the actual roles. This is not what I want though.

How do I instead create a dropdownlist for three strings in my Register View - "Please Select", "I am a clien开发者_运维技巧t", and "I am a vendor".

I have no hair left on this one and will be grateful to anyone who can help me to figure this one out. Thanks.

Something similar to below would work perfectly:

public class RegisterModel
{

    [Required]
    [Display(Name = "Role")]
    public string Role { get; set; }

Then you can have something similar to this in your view.

@Html.DropDownListFor(x => x.Role, new[] {
new SelectListItem() {Text = "I am a vendor", Value = "Vendor"},
new SelectListItem() {Text = "I am a client", Value = "Client"}
}, "Pick a basket")

Edit: String is a reference type and is nullable by default.

You can set the list values in the constructor: SelectList(dataObjects, valueField, textField)

    ViewBag.Roles = new SelectList(Roles.GetAllRoles().ToList(), "Id", "Name");

This allows you to define what attributes of your Role objects are being set as the values and texts of the options.