[源码分享]NPOI导出数据到EXCEl(输出文件，web输出下载)

来源：互联网发布：h5登录界面模板带源码编辑：程序博客网时间：2024/06/14 04:20

//从datereader（也可以使用datatable） 读取数据添加到excel工作簿，然后转换到内存流

public static MemoryStream RenderToExcel(IDataReader reader){    MemoryStream ms = new MemoryStream();     using (reader)    {        using (IWorkbook workbook = new HSSFWorkbook())        {            using (ISheet sheet = workbook.CreateSheet())            {                IRow headerRow = sheet.CreateRow(0);                int cellCount = reader.FieldCount;                 // handling header.                for (int i = 0; i < cellCount; i++)                {                    headerRow.CreateCell(i).SetCellValue(reader.GetName(i));                }                 // handling value.                int rowIndex = 1;                while (reader.Read())                {                    IRow dataRow = sheet.CreateRow(rowIndex);                     for (int i = 0; i < cellCount; i++)                    {                        dataRow.CreateCell(i).SetCellValue(reader[i].ToString());                    }                     rowIndex++;                }                 workbook.Write(ms);                ms.Flush();                ms.Position = 0;            }        }    }    return ms;}

//将内存流保存到文件

static void SaveToFile(MemoryStream ms, string fileName){    using (FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write))    {        byte[] data = ms.ToArray();         fs.Write(data, 0, data.Length);        fs.Flush();         data = null;    }}

//将内存流输出为下载文件

static void RenderToBrowser(MemoryStream ms, HttpContext context, string fileName){    if (context.Request.Browser.Browser == "IE")        fileName = HttpUtility.UrlEncode(fileName);    context.Response.AddHeader("Content-Disposition", "attachment;fileName=" + fileName);    context.Response.BinaryWrite(ms.ToArray());}