ajax 传递数组给后台.net MVC 控制器

 $.ajax({
                    type: "POST",
                    url: "/Registration/ManagementProject/DeleteProjectById",
                    dataType: "json",
                    data: {"selectData": that.UserIdArray },
                    async: false,
                    traditional: true,//这里设置为true
                    success: function (data) {
                        that.projectList = data;
                        console.log(data)
                        if (data.Response.ErrCode == "0") {
                            alert(data.Response.ErrMsg);
                            //清空已选择的数据
                            that.UserIdArray = [];
                            appList.GatProjectList(1);
                        }
                    }
                });

 /// <summary>
       /// 根据选中Id 删除项目
       /// </summary>
       /// <param name="selectData">选中的项目数组  也可以是List<string></param>
       /// <returns></returns>
        public IActionResult DeleteProjectById(string [] selectData)
        {
        }