ASP.NET MVC递归遍历菜单

 效果图：

SiteNavService

namespace DotNetMVC.Service
{
    public partial class SiteNavService : BaseService<SiteNav>, ISiteNavService
    {
        private IQueryable<SiteNav> GetJoinAll()
        {
            return GetAll()
                .Include(u => u.FunctionalModule)
                .AsNoTracking();
        }

        /// <summary>
        /// 获取菜单数据
        /// </summary>
        /// <returns></returns>
        public SiteNavDTO[] GetSiteNavs()
        {
            return GetJoinAll().OrderBy(e=>e.Sort).ThenBy(e=>e.Id).ToList().Select(p => ToDTO(p)).ToArray();
        }

        #region 递归获取菜单
        /// <summary>
        /// 递归获取菜单
        /// </summary>
        /// <param name="navLevel">菜单级数， 不指定，默认返回全部</param>
        /// <returns></returns>
        public List<SiteNavDTO> GetSiteNavsByLevel(int navLevel = 0)
        {
            SiteNavDTO[] allSiteNav = GetSiteNavs();
            return GetGetSiteNavs(allSiteNav, 0, navLevel);
        }

        /// <summary>
        /// 递归获取菜单
        /// </summary>
        /// <param name="allSiteNav"></param>
        /// <param name="parentId"></param>
        /// <param name="navLevel"></param>
        /// <returns></returns>
        private List<SiteNavDTO> GetGetSiteNavs(SiteNavDTO[] allSiteNav, long parentId, int navLevel)
        {
            List<SiteNavDTO> list = new List<SiteNavDTO>();
            //默认获取全部菜单
            IEnumerable<SiteNavDTO> childSiteNavs = allSiteNav.Where(e => e.ParentId == parentId);
            if (navLevel != 0)
            {
                //获取指定级数菜单
                childSiteNavs = childSiteNavs.Where(e => e.NavLevel <= navLevel);
            }

            //没有子菜单
            if (childSiteNavs.Count() <= 0)
            {
                return list;
            }

            foreach (SiteNavDTO dto in childSiteNavs)
            {
                list.Add(dto);
                //递归获取子菜单
                list.AddRange(GetGetSiteNavs(allSiteNav, dto.Id, navLevel));
            }

            return list;
        }
        #endregion

        private SiteNavDTO ToDTO(SiteNav entity)
        {
            SiteNavDTO dto = new SiteNavDTO();
            dto.CreateDateTime = entity.CreateDateTime;
            dto.Id = entity.Id;
            dto.FunctionalModuleId = entity.FunctionalModuleId;
            dto.ParentId = entity.ParentId;
            dto.NavLevel = entity.NavLevel;
            dto.NavName = entity.NavName;
            dto.NavTarget = entity.NavTarget;
            dto.NavUrl = entity.NavUrl;
            dto.NavImg = entity.NavImg;
            dto.ViewHtmlTemplate = entity.ViewHtmlTemplate;
            dto.ListHtmlTemplate = entity.ListHtmlTemplate;
            dto.Sort = entity.Sort;
            dto.IsShow = entity.IsShow;
            dto.IsEnabled = entity.IsEnabled;
            dto.Remark = entity.Remark;

            dto.FunName = entity.FunctionalModule.FunName;
            return dto;
        }
    }
}

SiteNavController

SiteNavAddGetViewModel model = new SiteNavAddGetViewModel();
List<SelectListItem> listSiteNav = new List<SelectListItem>();
listSiteNav.Add(new SelectListItem { Value = "0", Text="一级菜单" });
foreach (SiteNavDTO dto in siteNavService.GetSiteNavsByLevel())
{
    SelectListItem listItem = new SelectListItem();
    for (int i = 0; i < dto.NavLevel; i++)
    {
        dto.NavName = "|-" + dto.NavName;
    }
    listItem.Text = dto.NavName;
    listItem.Value = dto.Id.ToString();
    listItem.Selected = false;
    listSiteNav.Add(listItem);
}
model.ListSiteNav = listSiteNav;

View

<span class="select-box" style="width:150px;">
    @Html.DropDownList("parentNav", Model.ListSiteNav, new { @class = "select" })
</span>