asp.net 使用NPOI实现导出Excel功能

1. 导入NPOI包

在VS中打开NuGet包管理器，搜索”NPOI”：

选择列表中的NPOI在相应项目中进行安装，安装成功后会在项目中自动引用以下DLL：

2. 前台

function Export()  
{  
     location.href = "/Core/NPOIHandler.ashx?Type=Switch";  
} 

3. 后台处理

前台跳转至后台的一个一般处理程序，

3-1. 生成HSSFWorkbook数据源

 /// 

/// 生成交换机HSSFWorkbook数据源
/// 
/// 
/// 
/// 
/// 
private HSSFWorkbook BuildSwitchData(string sSheetName, string sAddress, string sOrganizationID)
{           
    try
    {
        HSSFWorkbook wb = new HSSFWorkbook();
        HSSFSheet sheet = (HSSFSheet)wb.CreateSheet(sSheetName); //创建工作表
        sheet.CreateFreezePane(0, 1); //冻结列头行
        HSSFRow row_Title = (HSSFRow)sheet.CreateRow(0); //创建列头行
        row_Title.HeightInPoints = 19.5F; //设置列头行高

        #region 设置列宽
        sheet.SetColumnWidth(0, 50 * 256);
        sheet.SetColumnWidth(1, 24 * 256);
        sheet.SetColumnWidth(2, 37 * 256);
        sheet.SetColumnWidth(3, 22 * 256);
        sheet.SetColumnWidth(4, 20 * 256);
        sheet.SetColumnWidth(5, 20 * 256);
        #endregion

        #region 设置列头单元格样式                
        HSSFCellStyle cs_Title = (HSSFCellStyle)wb.CreateCellStyle(); //创建列头样式
        cs_Title.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center; //水平居中
        cs_Title.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Center; //垂直居中
        HSSFFont cs_Title_Font = (HSSFFont)wb.CreateFont(); //创建字体
        cs_Title_Font.IsBold = true; //字体加粗
        cs_Title_Font.FontHeightInPoints = 12; //字体大小
        cs_Title.SetFont(cs_Title_Font); //将字体绑定到样式
        #endregion

        #region 生成列头
        for (int i = 0; i < 6; i++)
        {
            HSSFCell cell_Title = (HSSFCell)row_Title.CreateCell(i); //创建单元格
            cell_Title.CellStyle = cs_Title; //将样式绑定到单元格
            switch (i)
            {
                case 0:
                    cell_Title.SetCellValue("安装地址");
                    break;
                case 1:
                    cell_Title.SetCellValue("IP");
                    break;
                case 2:
                    cell_Title.SetCellValue("下行设备");
                    break;
                case 3:
                    cell_Title.SetCellValue("设备型号");
                    break;
                case 4:
                    cell_Title.SetCellValue("所属机构");
                    break;
                case 5:
                    cell_Title.SetCellValue("在线状态");
                    break;
            }
        }
        #endregion

        int iCount = 0;
        List lS = ExportDataHandler.BuildSwitchDataList(out iCount, null, null, sAddress, sOrganizationID); //项目中的数据源生成方法，此示例中请忽略
        if (lS != null)
        {
            for (int i = 0; i < lS.Count; i++)
            {
                #region 设置内容单元格样式
                HSSFCellStyle cs_Content = (HSSFCellStyle)wb.CreateCellStyle(); //创建列头样式
                cs_Content.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center; //水平居中
                cs_Content.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Center; //垂直居中
                #endregion

                #region 生成内容单元格
                HSSFRow row_Content = (HSSFRow)sheet.CreateRow(i + 1); //创建行
                row_Content.HeightInPoints = 16;
                for (int j = 0; j < 6; j++)
                {
                    HSSFCell cell_Conent = (HSSFCell)row_Content.CreateCell(j); //创建单元格
                    cell_Conent.CellStyle = cs_Content;
                    switch (j)
                    {
                        case 0:
                            cell_Conent.SetCellValue(lS[i].Address);
                            break;
                        case 1:
                            cell_Conent.SetCellValue(lS[i].IP);
                            break;
                        case 2:
                            cell_Conent.SetCellValue(lS[i].DownIP);
                            break;
                        case 3:
                            cell_Conent.SetCellValue(lS[i].SwitchTypeName);
                            break;
                        case 4:
                            cell_Conent.SetCellValue(lS[i].OrganizationName);
                            break;
                        case 5:
                            string sConnectState = Convert.ToString(lS[i].ConnecState);
                            if (sConnectState == null && sConnectState == "" || sConnectState == "1")
                                sConnectState = "正常";
                            else if (sConnectState == "0")
                                sConnectState = "不在线";
                            cell_Conent.SetCellValue(sConnectState);
                            break;
                    }
                }
                #endregion
            }
        }
        return wb;
    }
    catch { }
    return null;
}

3-2. 保存临时导出文件并Response至页面

public void ProcessRequest(HttpContext context)
 {
     try
     {
         string sExportFileName = ""; //导出的临时文件的名称
         string sExportFilePath = ""; //导出的临时文件路径
         try
         {
             HSSFWorkbook wb = null;
             string sFileName = "";
             string Type = context.Request.QueryString["Type"];
             switch (Type)
             {
                 case "Switch":
                     sFileName = "交换机列表";
                     wb = BuildSwitchData(sFileName, context.Request.QueryString["Address"], context.Request.QueryString["OrganizationID"]);
                     break;
                 default:
                     break;
             }
             string sWebBasePath = HttpContext.Current.Server.MapPath("~"); //获取网站根目录物理路径
             string sExportDir = sWebBasePath + "/Export"; //临时保存文件夹
             sExportFileName = sFileName + "_" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".xls";
             sExportFilePath = sExportDir + "/" + sExportFileName;
             if (!Directory.Exists(sExportDir))
                 Directory.CreateDirectory(sExportDir);

             using (FileStream file = new FileStream(sExportFilePath, FileMode.Create))
             {
                 wb.Write(file);
             }
         }
         catch
         {
             context.Response.Write("");
             if (File.Exists(sExportFilePath))
                 File.Delete(sExportFilePath);
             return;
         }
         context.Response.ContentType = "application/vnd.ms-excel";
         context.Response.AddHeader("Content-Disposition", "attachment;filename=" + sExportFileName);
         context.Response.TransmitFile(sExportFilePath); //将指定的文件直接写入 HTTP 响应输出流，而不在内存中缓冲该文件
         context.Response.Flush();
         if (File.Exists(sExportFilePath))
             File.Delete(sExportFilePath);
         context.Response.End();
     }
     catch { }
 }

4. 最终效果