按Excel的模板导出数据

思路：先配置模板数据，再Excel模板上传到服务器；然后下载excel模板；读取文档，写入数据，另存为新的文件

sql语句模板

 excel模板设置

然后就是导出的时候处理数据定义的字符串，按数据导出；注意读取的数据流要处理下，不然会报异常

        public Stream GetExcelStream(op_client_template_mapping model)//model  配置文件模型
        {
            string fileUrl = _BillFileService.GetHttp() + "/" + model.filePath + "/" + model.fileNames;
            return WebRequest.Create(fileUrl).GetResponse().GetResponseStream();
        }
        //文件里转换成能处理的流
        public MemoryStream StreamToMemoryStream(Stream instream)
        {
            MemoryStream outstream = new MemoryStream();
            const int bufferLen = 1024;
            byte[] buffer = new byte[bufferLen];
            int count = 0;
            while ((count = instream.Read(buffer, 0, bufferLen)) > 0)
            {
                outstream.Write(buffer, 0, count);
            }
            return outstream;
        }

excel模板

#region Excel模板
    public class ExcelModel
    {
        /// <summary>
        /// 标题位置
        /// </summary>
        public ExcelCloumn Title { get; set; }
        /// <summary>
        /// 列
        /// </summary>
        public List<ExcelCloumn> ExcelCloumns { get; set; }
    }

    public class ExcelCloumn
    {
        /// <summary>
        /// 列名(单号)
        /// </summary>
        public string cloumnName { get; set; }
        /// <summary>
        /// 字母（A）
        /// </summary>
        public string Letter { get; set; }
        /// <summary>
        /// 字母开始 （A1的取1）
        /// </summary>
        public int Index { get; set; }
        /// <summary>
        /// 字段名
        /// </summary>
        public string colunmEnglish { get; set; }
        /// <summary>
        /// 默认值
        /// </summary>
        public string DefaultValue { get; set; }
    }
    #endregion

按excel的模板文件存放位置以及获取模板

/// <summary>
    /// 模板文件
    /// </summary>
    public class op_client_template_mapping
    {
        public int index { get; set; }
        /// <summary>
        /// templateId
        /// </summary>        
        public int templateId { get; set; }
        /// <summary>
        /// 模板类型
        /// </summary>        
        public string categoryName { get; set; }
        /// <summary>
        /// 模板名称
        /// </summary>        
        public string templateName { get; set; }
        /// <summary>
        /// 模板文件
        /// </summary>        
        public string customerXML { get; set; }
        /// <summary>
        /// 创建时间
        /// </summary>        
        public DateTime cdate { get; set; }
        /// <summary>
        /// 创建人
        /// </summary>        
        public string cinput { get; set; }
        /// <summary>
        /// 是否是默认的
        /// </summary>        
        public bool is_sys { get; set; }
        /// <summary>
        /// 公式 2018.09.28新增
        /// </summary>
        public string formula { get; set; }   
        /// <summary>
        /// 文件存放路径
        /// </summary>
        public string filePath { get; set; }
        /// <summary>
        /// 文件名
        /// </summary>
        public string fileNames { get; set; }

        /// <summary>
        /// 文件数据
        /// </summary>
        public byte[] filedata { get; set; }
    }

处理下载的excel文件流

public MemoryStream StreamToMemoryStream(Stream instream)
        {
            MemoryStream outstream = new MemoryStream();
            const int bufferLen = 1024;
            byte[] buffer = new byte[bufferLen];
            int count = 0;
            while ((count = instream.Read(buffer, 0, bufferLen)) > 0)
            {
                outstream.Write(buffer, 0, count);
            }
            return outstream;
        }

处理模板数据，我保存的是字符串

 #region 处理字符串
        public ExcelModel HandelString(string customerXML, List<ColunmData> colunmData)
        {
            ExcelModel excelModel = new ExcelModel();
            if (customerXML.Contains("<标题>") && customerXML.Contains("</标题>"))
            {
                string title = SubString(customerXML, "标题");
                excelModel.Title = HandelEqe(title, colunmData);
            }
            if (customerXML.Contains("<头部>") && customerXML.Contains("</头部>"))
            {
                string cloumns = SubString(customerXML, "头部");
                string[] data = cloumns.Replace("
", "").Split('
');
                List<ExcelCloumn> excelCloumn = new List<ExcelCloumn>();
                for (int i = 0; i < data.Count(); i++)
                {
                    excelCloumn.Add(HandelEqe(data[i], colunmData));
                }
                excelModel.ExcelCloumns = excelCloumn;
            }
            return excelModel;
        }
        /// <summary>
        /// 截取字符串
        /// </summary>
        private string SubString(string customerXML, string name)
        {
            int stateIndex = customerXML.IndexOf("<" + name + ">") + 4;
            int endIndex = customerXML.IndexOf("</" + name + ">");
            return customerXML.Substring(stateIndex, endIndex - stateIndex).Trim();
        }

        private ExcelCloumn HandelEqe(string cloumn, List<ColunmData> colunmData)
        {
            ExcelCloumn model = new ExcelCloumn();
            if (cloumn.Contains("="))
            {
                string[] str = cloumn.Split('=');
                model.cloumnName = str[0].Trim();
                if (str.Length > 1)
                {
                    Regex reg = new Regex(@"[1-9]d*");
                    model.Index = Common.Utils.ObjToInt(reg.Match(str[1]).Value, 1);
                    model.Letter = str[1].Replace(model.Index.ToString(), "").Trim();
                }
                if (str.Length > 2)
                {
                    model.DefaultValue = str[2].Trim();
                }
            }
            else
            {
                model.cloumnName = cloumn.Trim();
            }
            model.colunmEnglish = colunmData.Where(it => it.colunmName == model.cloumnName).FirstOrDefault()?.colunmEnglish ?? "";
            return model;
        }
        #endregion

导出数据大概

public void AsposeToExcel<T>(List<T> data, ExcelModel excelModel, op_client_template_mapping mapping, string path)
        {
            try
            {
                Stream sm = GetExcelStream(mapping);
                var ms = StreamToMemoryStream(sm);
                ms.Seek(0, SeekOrigin.Begin); int buffsize = (int)ms.Length; //rs.Length 此流不支持查找,先转为MemoryStream
                byte[] bytes = new byte[buffsize];

                ms.Read(bytes, 0, buffsize);
                Workbook workbook = new Workbook(ms);
                ms.Flush(); ms.Close();
                sm.Flush(); sm.Close();
                Worksheet worksheet = workbook.Worksheets[0]; //工作表

                if (excelModel.Title != null && !string.IsNullOrEmpty(excelModel.Title?.cloumnName))
                {
                    SetTitle(worksheet, excelModel.Title.cloumnName, excelModel.Title.Letter + excelModel.Title.Index);
                }
                SetCellData(worksheet, data, excelModel);

                workbook.Save(path);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }

        private static void SetTitle(Worksheet sheet, string title, string index)
        {
            sheet.Cells[index].PutValue(title);
        }

        /// <summary>
        /// 填充字段
        /// </summary>
        private static void SetCellData<T>(Worksheet sheet, List<T> data, ExcelModel excelModel)
        {
            var noData = excelModel.ExcelCloumns.Where(it => it.colunmEnglish.Equals(""));//没有绑定的数据取默认值
            int i = 0;
            foreach (T item in data)
            {
                foreach (PropertyDescriptor pd in TypeDescriptor.GetProperties(typeof(T)))
                {
                    var column = excelModel.ExcelCloumns.Where(it => it.colunmEnglish.Equals(pd.Name)).FirstOrDefault();
                    if (column != null)//存在该字段就赋值
                    {
                        int row = column.Index + i;
                        if (pd.PropertyType.ToString() == "System.DateTime")
                        {
                            sheet.Cells[column.Letter + row].PutValue(pd.GetValue(item).ToString());//（column.Letter + row）等于 A2，C2这样赋值
                        }
                        else
                        {
                            sheet.Cells[column.Letter + row].PutValue(pd.GetValue(item));
                        }
                    }
                }
                foreach (var it in noData)//赋值默认值
                {
                    int row = it.Index + i;
                    if (it.cloumnName == "序号")
                    {
                        sheet.Cells[it.Letter + row].PutValue(i+1);
                    }
                    else
                    {
                        sheet.Cells[it.Letter + row].PutValue(it.DefaultValue ?? "");
                    }
                }
                i++;
            }
            sheet.AutoFitColumns();
        }
        #endregion