封装Excls数据导出功能 返回一个下载链接地址

   /// <summary>
        /// 获取本地存储地址
        /// </summary>
        /// <param name="dt"></param>
        /// <param name="prefix">前缀类别</param>
        /// <returns></returns>
        public string GetDwonLoadlPath(DataTable dt, string prefix)
        {
            string filename = System.Configuration.ConfigurationManager.AppSettings[prefix].ToString() + Guid.NewGuid() + ".xlsx";
            string filePath = System.Web.Hosting.HostingEnvironment.ApplicationPhysicalPath + "\File\Download\" + filename;
            string returnpath = System.Web.Hosting.HostingEnvironment.ApplicationVirtualPath + "/File/Download/" + filename;
            ExcelHelper.DataTableToExcel(dt, filePath);
            return System.Configuration.ConfigurationManager.AppSettings["DomainName"] + returnpath;
        }

    public class TransitionHelper
    {
        private static volatile TransitionHelper drugParamsHelper = null;
        private static object syncRoot = new Object();
        public TransitionHelper()
        {

        }
        /// <summary>
        /// 初始化注册
        /// </summary>
        public static TransitionHelper Instance
        {
            get
            {
                if (drugParamsHelper == null)
                {
                    lock (syncRoot)
                    {
                        if (drugParamsHelper == null)
                        {
                            drugParamsHelper = new TransitionHelper();
                        }
                    }
                }
                return drugParamsHelper;
            }
        }
        /// <summary>
        /// 获取本地存储地址
        /// </summary>
        /// <param name="dt"></param>
        /// <param name="prefix">前缀类别</param>
        /// <returns></returns>
        public string GetDwonLoadlPath<T>(List<T> list,Dictionary<string,string> dic, string path)
        {
            DataTable dataTable = ListTranDataTableHelper.ToDataTable(list, dic); 
            return GetDwonLoadlPath(dataTable, path);
        }

        public string GetDwonLoadlPath(DataTable dt, string path)
        {
            string Domain = AppsettingsHelper.app(new string[] { "ApplicationDomain" }).ObjToString();
            string subpath = @"/Export/";
            string fullpath = path + subpath;
            DicCreate(fullpath);
            string filename = Guid.NewGuid() + ".xlsx";
            string fullfilepath = fullpath + filename;
            EplusExcleHelper.DataTableToExcel(dt, fullfilepath);
            return Domain+subpath+filename;
        }

        /// <summary>
        /// 文件目录如果不存在，就创建一个新的目录
        /// </summary>
        /// <param name="path"></param>
        private void DicCreate(string path)
        {
            if (!Directory.Exists(path))
            {
                Directory.CreateDirectory(path);
            }
        }
    }

调用示例 

string filepath = TransitionHelper.Instance.GetDwonLoadlPath(list, RenameColumDic, webRootPath); 
 //转换列名称成中文名
            Dictionary<string, string> RenameColumDic = new Dictionary<string, string>();
            queryParams.colCollection.ForEach(f =>
            {
                RenameColumDic.Add(f.FieldName, f.DisplayName);
            });
            //将对象转成datatble
            DataTable dataTable = ListTranDataTableHelper.ToDataTable<ClinicalRegistrationCach>(list, RenameColumDic, queryParams.colCollection.Select(c => c.FieldName).ToArray());
            return new Response<string>(DrugParamsHelper.Instance.GetDwonLoadlPath(dataTable, "CDEExclsName"));