Ajax调用web api方法

我有这样的视图:

 <div id="addDisplay" class="display">
                <div class="box-header">
                    <h3 class="box-title">Ajouter un compte</h3>
                </div>
                @{
                    AjaxOptions addAjaxOpts = new AjaxOptions
                    {
                        // options will go here
                        OnSuccess = "getData", 
                        OnFailure="selectView('add')",
                        HttpMethod = "Post",
                        Url = "/api/AccountManage/CreateAccount"
                    };
                }
                @using (Ajax.BeginForm(addAjaxOpts))
                {
                @Html.Hidden("id", 0)
                <p>
                    <label>Statut social   </label>
                    <select id="marital_status" name="marital_status">
                        <option value="Mr">Monsieur</option>
                        <option value="MLLE">Mademoiselle</option>
                        <option value="MME">Madame</option>
                    </select>

                </p>
                <p><label>Nom   </label>@Html.Editor("Nom")<label style="color:red" id="labError"> ( * )</label></p>
                <p><label>Prenom   </label>@Html.Editor("Prenom")<label style="color:red" id="labError"> ( * )</label></p>
                <p><label>Adresse   </label>@Html.TextArea("address")<label style="color:red" id="labError"> ( * )</label></p>
                <p><label>Pseudo   </label>@Html.Editor("Username")<label style="color:red" id="labError"> ( * )</label></p>
                <p><label>Email   </label>@Html.Editor("Email")<label style="color:red" id="labError">Entrer une adresse mail valide</label></p>
                <p><label>Mot de passe   </label>@Html.Editor("Password")<label style="color:red" id="labError">Doit contenir au moins une lettre majuscule, une minuscule, un chiffre et un caractère spécial</label></p>
                <p>
                    <label>Rôle</label>
                    <select id="Role" name="Role">
                        <option value="adminpark">Administrateur Park</option>
                        <option value="chauffeur">Chauffeur</option>
                        @if (User.IsInRole("admin") || User.IsInRole("manager") || User.IsInRole("superadmin"))
                            {
                            <option value="employe">Employé</option>
                                if (User.IsInRole("superadmin"))
                                {
                            <option value="admin">Administrateur</option>
                            <option value="manager">Manager</option>
                                }
                            }
                    </select>
                </p>
                  <button type="submit" class="btn btn-primary" id="AddNew">Enregistrer</button>
                  <button type="button" class="btn bg-maroon btn-flat margin" id="Annuler">Annuler</button>
                }
            </div>

对于它，我使用了下面的脚本:

$(document).ready(function () { 
selectView("summary");
getData();
$("button").click(function (e) {

    var selectedRadio = $('input:radio:checked')
    switch (e.target.id) {
        case "refresh":
            getData();
            break;
        case "delete":
            $.ajax({
                type: "Delete",
                url: "/api/AccountManage/DeleteAccount/" + selectedRadio.attr('value'),
                success: function (data) {
                    selectedRadio.closest('tr').remove();
                }
            });
            break;

           case "add":
               selectView("add");
               $('#Nom').val("");
               $('#Prenom').val("");
               $('#adress').val("");
               $('#Username').val("");
               $('#Email').val("");
               $('#Password').val("");
            break;

        case "edit":          
            $.ajax({
                type: "GET",
                url: "/api/AccountManage/GetCollaborator/" + selectedRadio.attr('value'),
                success: function (data) {
                    $('#editid').val(data.id);
                    $('#editiduser').val(data.id_user_fk);
                    $('#editNom').val(data.Nom);
                    $('#editPrenom').val(data.Prenom);
                    $('#editAdresse').val(data.address);
                    selectView("edit");
                }
            });
            break;
        case "submitEdit":
            $.ajax({
                type: "PUT",
                url: "/api/AccountManage/UpdateAccount/" + selectedRadio.attr('value'),
                data: $('#editForm').serialize(),
                success: function (result) {
                    if (result) {
                        var cells = selectedRadio.closest('tr').children(); 
                        cells[1].innerText = $('#editNom').val();
                        cells[2].innerText = $('#editPrenom').val(); 
                        cells[3].innerText = $('#Role').val(); 
                        selectView("summary");
                    }
                },
                error:  selectView("edit")
            });
            break;
        case "Annuler":
            selectView("summary");
            break;
    }
});
                           });

在控制器中我有这个方法:

  [HttpPost]
        public System.Web.Mvc.JsonResult CreateAccount(CollaborateurModel item)
        {
            var user = new ApplicationUser { UserName = item.Username, Email = item.Email };
            if (UserManager.FindByEmail(item.Email) == null) 
            {
                var result = UserManager.CreateAsync(user, item.Password).Result;
            } 
            if(ModelState.IsValid)
            {
                var currentUser = UserManager.FindByName(item.Username);
                var roleresult = UserManager.AddToRole(currentUser.Id, item.Role);
                ajt_collaborator entity = Mapper.Map<CollaborateurModel, ajt_collaborator>(item);
                entity.id_user_fk = currentUser.Id;
                entity.is_deleted = false; 
                repo.CreateCollaborator(entity);
                return new System.Web.Mvc.JsonResult { Data = true };
            }
            else
            {
                return new System.Web.Mvc.JsonResult { Data = false };
            }
        }

问题是，如果我提交表单，并调试代码的web api方法达到三次，每次点击提交!!我不明白这是为什么。我的WebApiConfig只包含以下代码片段:

 public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        config.Routes.MapHttpRoute(
         name: "DefaultApi",
         routeTemplate: "api/{controller}/{action}/{id}",
         defaults: new { id = RouteParameter.Optional }
       );
        config.Routes.MapHttpRoute(
           name: "DefaultApi2",
           routeTemplate: "api/{controller}" 
       );
    }
}

所以我需要知道:

1. 为什么会这样?
2. 我该如何修复它?

$("button").click(function (e)

$("button").click(function (e)
 e.preventDefault();