常见的C#实现导出到Excel 功能

报表在生产中的应用非常广泛，项目中也会经常需要实现将自动生成报表，并导出到Excel 中的功能。以下是对该功能实现的一点总结。

1.利用GridView自带的导出功能

图1.1 页面呈现效果

   

1.2 导出到 Excel里的效果

前台直接拖放一个GridView控件。

后台代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
using System.IO;
using System.Text;
using System.Web.UI.HtmlControls;//加上这个命名空间才能使用HtmlForm类


namespace WebToExcel03
{
    /// <summary>
    /// GridView自带的属性
    /// </summary>
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if(!IsPostBack)
            {
                Gv_Bind();
            }
        }

        public void Gv_Bind()
        {
            string connStr = "Data Source=20110814-1820;Initial Catalog=NewHeleScann;Integrated Security=True";
            string sql = "select * from Scan_JiDiTable ";
            SqlConnection conn = new SqlConnection(connStr);
            SqlDataAdapter sdp = new SqlDataAdapter(sql, conn);
            DataSet ds = new DataSet();
            sdp.Fill(ds);
            GridView1.DataSource = ds;
            GridView1.DataBind();
        }

       
        //在页面重写Web基类  否则报错:控件必须放在具有 runat=server 的窗体标记内"错误
        public override void VerifyRenderingInServerForm(Control control)
        {
            // Confirms that an HtmlForm control is rendered for
        }
         
        private void ExportExcelFromDataGrid(string filename, GridView ToExcelGrid)
        {
            /* 传说此方法更好，可以让我们不用重写VerifyRenderingInServerForm方法
             * 但是这里未调试成功
            StringBuilder sb = new StringBuilder();
            StringWriter sw = new StringWriter(sb);
            HtmlTextWriter htw = new HtmlTextWriter(sw);

            Page page = new Page();
            HtmlForm form = new HtmlForm();

            ToExcelGrid.EnableViewState = false;

            // Deshabilitar la validación de eventos, sólo asp.net 2
            page.EnableEventValidation = false;

            // Realiza las inicializaciones de la instancia de la clase Page que requieran los diseñadores RAD.
            page.DesignerInitialize();

            page.Controls.Add(form);
            form.Controls.Add(ToExcelGrid);

            page.RenderControl(htw);
             */
            Response.ClearHeaders();
            Response.Clear();
            Response.Expires = 0;
            Response.Buffer = true;
            Response.HeaderEncoding = System.Text.Encoding.UTF8;
            //  Response.Charset = "utf-8";
            Response.AppendHeader("Content-Disposition", "attachment;filename=" + Server.UrlEncode(filename));
            Response.ContentEncoding = System.Text.Encoding.Default;//设置输出流为简体中文   
            //  Response.ContentType = "application/ms-excel";//设置输出文件类型为excel文件。  
            Response.ContentType = "Application/octet-stream";
            this.EnableViewState = false;
            System.Globalization.CultureInfo myCItrad = new System.Globalization.CultureInfo("zh-CHS", true);
            System.IO.StringWriter oStringWriter = new System.IO.StringWriter(myCItrad);
            System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
            ToExcelGrid.RenderControl(oHtmlTextWriter);
            Response.Write(oStringWriter.ToString());
            Response.End();
        }

        protected void ToExcel_Click(object sender, EventArgs e)
        {
            string filename = "ToExcel" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".xls" ;
            ExportExcelFromDataGrid(filename, GridView1);
        }
    }
}

2 采用COM.Excel组件实现导出到Excel

COM.Excel是一个外部组件，所以首先要在当前项目中，添加对它的引用。

单击项目，右键选择“添加引用”，找到该组件，添加完成后效果如下：

为了方便查看数据，这里也在前台放了一个GridView控件(实际上与导出没有关系)。

导出效果如下：

后台源码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
using System.Collections;

namespace ToExcelCom
{
    /// <summary>
    /// 采用COM.Excel组件实现导出到Excel
    /// </summary>
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if(!IsPostBack)
            {
                //获取ds
                DataSet ds = GetDs();
                //绑定到GridView
                GridView1.DataSource = ds;
                GridView1.DataBind();
            }
        }

        public DataSet GetDs()
        {
            string connStr = "Data Source=20110814-1820;Initial Catalog=NewHeleScann;Integrated Security=True";
            string sql = "select * from Scan_JiDiTable ";
            SqlConnection conn = new SqlConnection(connStr);
            SqlDataAdapter sdp = new SqlDataAdapter(sql, conn);
            DataSet ds = new DataSet();
            sdp.Fill(ds);
            return ds;
        }

        protected void ToExcel_Click(object sender, EventArgs e)
        {
            string path = System.Web.HttpContext.Current.Server.MapPath("~/SaveExcelFiles/");//保存路径
            //string filename = comm.OutputExcel(ds.Tables[0], DDLName.SelectedItem.Text.ToString(), path);//保存文件
            Hashtable hs = new Hashtable();//表列名
            DataSet ds = GetDs();
            //循环添加表列名
            foreach (DataColumn dc in ds.Tables[0].Columns)
            {
                hs.Add(dc.ColumnName, dc.ColumnName);
            }
            //DataTable dts = ds.Tables[0];
            DataTable[] dts = { ds.Tables[0]};//数据集的集合
            string strTitle = "";
            string filename = DataExcels(dts ,strTitle, path, hs);
            System.Web.HttpContext.Current.Response.Clear();
            System.Web.HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + filename);
            System.Web.HttpContext.Current.Response.ContentType = "application/ms-excel";
            System.Web.HttpContext.Current.Response.TransmitFile(path + filename);//打开文件
            //System.Web.HttpContext.Current.Response.TransmitFile(filename);//打开文件
            System.Web.HttpContext.Current.Response.End();
        }
        /// <summary>
        /// 
        /// </summary>
        /// <param name="dts"></param>
        /// <param name="strTitle"></param>
        /// <param name="FilePath"></param>
        /// <param name="nameList"></param>
        /// <param name="titles"></param>
        /// <returns></returns>
         public string DataExcels(System.Data.DataTable[] dts, string strTitle, string FilePath, Hashtable nameList)
        {
            COM.Excel.cExcelFile excel = new COM.Excel.cExcelFile();
            //当文件大于10的时候   清空所有文件！！！
            ClearFile(FilePath);
            //文件名
            string filename = strTitle+ DateTime.Now.ToString("yyyyMMddHHmmssff") + ".xls";
            //生成相应的文件
            excel.CreateFile(FilePath + filename);
            //设置margin
            COM.Excel.cExcelFile.MarginTypes mt1 = COM.Excel.cExcelFile.MarginTypes.xlsTopMargin;
            COM.Excel.cExcelFile.MarginTypes mt2 = COM.Excel.cExcelFile.MarginTypes.xlsLeftMargin;
            COM.Excel.cExcelFile.MarginTypes mt3 = COM.Excel.cExcelFile.MarginTypes.xlsRightMargin;
            COM.Excel.cExcelFile.MarginTypes mt4 = COM.Excel.cExcelFile.MarginTypes.xlsBottomMargin;
            double height = 2.2;
            excel.SetMargin(ref mt1, ref height);
            excel.SetMargin(ref mt2, ref height);
            excel.SetMargin(ref mt3, ref height);
            excel.SetMargin(ref mt4, ref height);
            //设置字体！！
            COM.Excel.cExcelFile.FontFormatting ff = COM.Excel.cExcelFile.FontFormatting.xlsNoFormat;
            string font = "宋体";
            short fontsize = 14;
            excel.SetFont(ref font, ref fontsize, ref ff);
            byte b1 = 1, b2 = 12;
            short s3 = 12;
            excel.SetColumnWidth(ref b1, ref b2, ref s3);

            string header = "页眉";
            string footer = "页脚";
            excel.SetHeader(ref header);
            excel.SetFooter(ref footer);

            COM.Excel.cExcelFile.ValueTypes vt = COM.Excel.cExcelFile.ValueTypes.xlsText;
            COM.Excel.cExcelFile.CellFont cf = COM.Excel.cExcelFile.CellFont.xlsFont0;
            COM.Excel.cExcelFile.CellAlignment ca = COM.Excel.cExcelFile.CellAlignment.xlsCentreAlign;
            COM.Excel.cExcelFile.CellHiddenLocked chl = COM.Excel.cExcelFile.CellHiddenLocked.xlsNormal;
            // 报表标题
            int cellformat = 1;      
            int rowIndex = 1;//起始行
            int colIndex = 0;
            foreach (System.Data.DataTable dt in dts)
            {               
                colIndex = 0;
                //取得列标题                
                foreach (DataColumn colhead in dt.Columns)
                {
                    colIndex++;
                    string name = colhead.ColumnName.Trim();
                    object namestr = (object)name;
                    excel.WriteValue(ref vt, ref cf, ref ca, ref chl, ref rowIndex, ref colIndex, ref namestr, ref cellformat);
                }
                //取得表格中的数据            
                foreach (DataRow row in dt.Rows)
                {
                    rowIndex++;
                    colIndex = 0;
                    foreach (DataColumn col in dt.Columns)
                    {
                        colIndex++;
                        if (col.DataType == System.Type.GetType("System.DateTime"))
                        {     
                            object str = (object)(Convert.ToDateTime(row[col.ColumnName].ToString())).ToString("yyyy-MM-dd"); ;
                            excel.WriteValue(ref vt, ref cf, ref ca, ref chl, ref rowIndex, ref colIndex, ref str, ref cellformat);
                        }
                        else
                        {
                            object str = (object)row[col.ColumnName].ToString();
                            excel.WriteValue(ref vt, ref cf, ref ca, ref chl, ref rowIndex, ref colIndex, ref str, ref cellformat);
                        }
                    }
                }
                rowIndex += 3 ;
            }
            int ret = excel.CloseFile();          
            //return FilePath+filename;
            return filename;
        }

         #region  清理过时的Excel文件

         private void ClearFile(string FilePath)
         {
             String[] Files = System.IO.Directory.GetFiles(FilePath);
             if (Files.Length > 10)
             {
                 for (int i = 0; i < 10; i++)
                 {
                     try
                     {
                         System.IO.File.Delete(Files[i]);
                     }
                     catch
                     {
                     }

                 }
             }
         }
         #endregion
    }
}

对比两种导出的效果，显然第二种更加人性化一些。当然这两种方法，基本都被普遍使用。

3.使用asposecell组件，详细参考http://www.cnblogs.com/whitewolf/archive/2011/03/21/Aspose_Cells_Template1.html#commentform

该组件确实强大，比较好用，Excel模板可以事先做好，很直观，对于格式比较复杂的报表，优势明显。

效果如下：

这种方案，在http://www.cnblogs.com/whitewolf/archive/2011/03/21/Aspose_Cells_Template1.html#commentform有很详细的演示，这里不再獒述。

但是也有人从性能方面提出了更好的方案，如通过SSIS 包的实现，据说这种方案主要是针对于较大数据量的报表性能卓越，我认为值得尝试。