C# DataTable 导出 Excel 进阶 多行表头、合并单元格、中文文件名乱码

本文原创地址：http://blog.csdn.net/ranbolwb/article/details/8083983 ，转载请保留本行。

本例子是上一篇 DataTable 导出 Excel 的进阶，除了上一篇提到的处理乱码问题，本例还添加了处理多行表头、合并单元格的功能及处理中文文件名乱码问题，应该可以满足日常开发的需要了。

废话不多说了，直接上代码：

using System;
using System.Collections.Generic;
using System.Web;
using System.Configuration;
using System.Data;
using System.Data.Common;
using System.Data.OleDb;
using System.Web.UI.WebControls;
using System.Text.RegularExpressions;

/// <summary>
/// Common 的摘要说明
/// 作者：李伟波
/// 时间：2012-10-18
/// </summary>
public class Common
{
    public Common()
    {
        //
        //TODO: 在此处添加构造函数逻辑
        //
    }

    /// <summary>
    /// 描述：把DataTable内容导出excel并返回客户端 
    /// 作者：李伟波
    /// 时间：2012-10-18
    /// </summary>
    /// <param name="dtData"></param>
    /// <param name="header"></param>
    /// <param name="fileName"></param>
    /// <param name="mergeCellNums">要合并的列索引字典 格式：列索引-合并模式(合并模式 1 合并相同项、2 合并空项、3 合并相同项及空项)</param>
    /// <param name="mergeKey">作为合并项的标记列索引</param>
    public static void DataTable2Excel(System.Data.DataTable dtData, TableCell[] header, string fileName, Dictionary<int, int> mergeCellNums, int? mergeKey)
    {
        System.Web.UI.WebControls.GridView gvExport = null;
        // 当前对话 
        System.Web.HttpContext curContext = System.Web.HttpContext.Current;
        // IO用于导出并返回excel文件 
        System.IO.StringWriter strWriter = null;
        System.Web.UI.HtmlTextWriter htmlWriter = null;

        if (dtData != null)
        {
            // 设置编码和附件格式 
            curContext.Response.ContentType = "application/vnd.ms-excel";
            curContext.Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
            curContext.Response.Charset = "gb2312";
            if (!string.IsNullOrEmpty(fileName))
            {
                //处理中文名乱码问题
                fileName = System.Web.HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8);
                curContext.Response.AppendHeader("Content-Disposition", ("attachment;filename=" + (fileName.ToLower().EndsWith(".xls") ? fileName : fileName + ".xls")));
            }
            // 导出excel文件 
            strWriter = new System.IO.StringWriter();
            htmlWriter = new System.Web.UI.HtmlTextWriter(strWriter);

            // 重新定义一个无分页的GridView 
            gvExport = new System.Web.UI.WebControls.GridView();
            gvExport.DataSource = dtData.DefaultView;
            gvExport.AllowPaging = false;
            //优化导出数据显示，如身份证、12-1等显示异常问题
            gvExport.RowDataBound += new System.Web.UI.WebControls.GridViewRowEventHandler(dgExport_RowDataBound);

            gvExport.DataBind();
            //处理表头
            if (header != null && header.Length > 0)
            {
                gvExport.HeaderRow.Cells.Clear();
                gvExport.HeaderRow.Cells.AddRange(header);
            }
            //合并单元格
            if (mergeCellNums != null && mergeCellNums.Count > 0)
            {
                foreach (int cellNum in mergeCellNums.Keys)
                {
                    MergeRows(gvExport, cellNum, mergeCellNums[cellNum], mergeKey);
                }
            }

            // 返回客户端 
            gvExport.RenderControl(htmlWriter);
            curContext.Response.Clear();
            curContext.Response.Write("<meta http-equiv=\"content-type\" content=\"application/ms-excel; charset=gb2312\"/>" + strWriter.ToString());
            curContext.Response.End();
        }
    }
    /// <summary>
    /// 描述：行绑定事件
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected static void dgExport_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            foreach (TableCell cell in e.Row.Cells)
            {
                //优化导出数据显示，如身份证、12-1等显示异常问题
                if (Regex.IsMatch(cell.Text.Trim(), @"^\d{12,}$") || Regex.IsMatch(cell.Text.Trim(), @"^\d+[-]\d+$"))
                {
                    cell.Attributes.Add("style", "vnd.ms-excel.numberformat:@");
                }
            }
        }
    }

    /// <summary>   
    /// 描述：合并GridView列中相同的行
    /// 作者：李伟波
    /// 时间：2012-10-18
    /// </summary>   
    /// <param   name="gvExport">GridView对象</param>   
    /// <param   name="cellNum">需要合并的列</param>   
    /// <param name="mergeMode">合并模式 1 合并相同项、2 合并空项、3 合并相同项及空项</param>
    /// <param name="mergeKey">作为合并项的标记列索引</param>
    public static void MergeRows(GridView gvExport, int cellNum, int mergeMode, int? mergeKey)
    {
        int i = 0, rowSpanNum = 1;
        System.Drawing.Color alterColor = System.Drawing.Color.LightGray;
        while (i < gvExport.Rows.Count - 1)
        {
            GridViewRow gvr = gvExport.Rows[i];
            for (++i; i < gvExport.Rows.Count; i++)
            {
                GridViewRow gvrNext = gvExport.Rows[i];
                if ((!mergeKey.HasValue || (mergeKey.HasValue && (gvr.Cells[mergeKey.Value].Text.Equals(gvrNext.Cells[mergeKey.Value].Text) || " ".Equals(gvrNext.Cells[mergeKey.Value].Text)))) && ((mergeMode == 1 && gvr.Cells[cellNum].Text == gvrNext.Cells[cellNum].Text) || (mergeMode == 2 && " ".Equals(gvrNext.Cells[cellNum].Text.Trim())) || (mergeMode == 3 && (gvr.Cells[cellNum].Text == gvrNext.Cells[cellNum].Text || " ".Equals(gvrNext.Cells[cellNum].Text.Trim())))))
                {
                    gvrNext.Cells[cellNum].Visible = false;
                    rowSpanNum++;
                    //gvrNext.BackColor = gvr.BackColor;  //2016.4.18 处理个别电脑可能会出现底色不变的问题
                    if (alterColor == System.Drawing.Color.White)
                        gvrNext.BackColor = System.Drawing.Color.LightGray;
                }
                else
                {
                    gvr.Cells[cellNum].RowSpan = rowSpanNum;
                    rowSpanNum = 1;
                    //间隔行加底色，便于阅读
                    if (mergeKey.HasValue && cellNum == mergeKey.Value)
                    {
                        if (alterColor == System.Drawing.Color.White)
                        {
                            gvr.BackColor = System.Drawing.Color.LightGray;
                            alterColor = System.Drawing.Color.LightGray;
                        }
                        else
                        {
                            alterColor = System.Drawing.Color.White;
                        }
                    }
                    break;
                }
                if (i == gvExport.Rows.Count - 1)
                {
                    gvr.Cells[cellNum].RowSpan = rowSpanNum;
                    if (mergeKey.HasValue && cellNum == mergeKey.Value)
                    {
                        if (alterColor == System.Drawing.Color.White)
                            gvr.BackColor = System.Drawing.Color.LightGray;
                    }
                }
            }
        }
    }
}

页面调用如下：

        TableCell[] header = new TableCell[29];
        for (int i = 0; i < header.Length; i++)
        {
            header[i] = new TableHeaderCell();
        }
        header[0].ColumnSpan = 7;
        header[0].Text = "订单基本信息";
        header[1].ColumnSpan = 4;
        header[1].Text = "收货人信息";
        header[2].ColumnSpan = 4;
        header[2].Text = "快递信息";
        header[3].ColumnSpan = 3;
        header[3].Text = "支付信息";
        header[4].ColumnSpan = 6;
        header[4].Text = "商品信息</th></tr><tr>";
        //第二行
        header[5].Text = "订单编号";
        header[6].Text = "订单类型";
        header[7].Text = "订单状态";
        header[8].Text = "下单时间";
        header[9].Text = "支付时间";
        header[10].Text = "发货时间";
        header[11].Text = "备注";

        header[12].Text = "收货人姓名";
        header[13].Text = "地址";
        header[14].Text = "手机号码";
        header[15].Text = "配送方式";

        header[16].Text = "物流公司名称";
        header[17].Text = "物流发货单";
        header[18].Text = "运费收入";
        header[19].Text = "实际配送费";

        header[20].Text = "订单总额";
        header[21].Text = "支付方式";
        header[22].Text = "订单支付金额";

        header[23].Text = "商品编号";
        header[24].Text = "商品名称";
        header[25].Text = "商品价格";
        header[26].Text = "购买数量";
        header[27].Text = "商品总金额";
        header[28].Text = "优惠金额</th>";

        DataTable dt = Common.DbHelper.DBClass_GetDataToTable(sqlDHD, sqlParam, ref rMsg);

        Dictionary<int, int> mergeCellNums = new Dictionary<int, int>();
        for (int i = 0; i < dt.Columns.Count; i++)
        {
            mergeCellNums.Add(i, 2);
        }
        Common.DataTable2Excel(dt, header, "数据导出" + DateTime.Now.ToString("yyyyMMdd"), mergeCellNums, 0);

以上代码未经严格测试，或有错漏，请引用或使用本文代码的诸君注意。

导出效果如下图：