Question

我正试图像这样使用NPOI：

private Stream RenderDataTableToExcel(DataTable SourceTable)
{
    XSSFWorkbook workbook = null;
    MemoryStream ms = null;
    ISheet sheet = null;
    XSSFRow headerRow = null;
    try
    {
        workbook = new XSSFWorkbook();
        ms = new MemoryStream();
        sheet = workbook.CreateSheet();
        headerRow = (XSSFRow)sheet.CreateRow(0);
        foreach(DataColumn column in SourceTable.Columns)
            headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
        int rowIndex = 1;
        foreach(DataRow row in SourceTable.Rows)
        {
            XSSFRow dataRow = (XSSFRow)sheet.CreateRow(rowIndex);
            foreach(DataColumn column in SourceTable.Columns)
                dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
            ++rowIndex;
        }
        for (int i = 0; i <= SourceTable.Columns.Count; ++i)
            sheet.AutoSizeColumn(i);
        workbook.Write(ms);
        ms.Flush();
    }
    catch (Exception ex)
    {
        return null;
    }
    finally
    {
        ms.Close();
        sheet = null;
        headerRow = null;
        workbook = null;
    }
    return ms;
}
private void DownloadExcel(DataTable dt, string reportName)
{
    Stream s = RenderDataTableToExcel(dt);
    if (s != null)
    {
        MemoryStream ms = s as MemoryStream;
        Response.AddHeader("Content-Disposition", string.Format("attachment;filename=" + HttpUtility.UrlEncode(reportName) + DateTime.Now.ToString("yyyyMMdd") + ".xlsx"));
        Response.ContentType = "application/vnd.ms-excel";
        Response.AddHeader("Content-Length", ms.ToArray().Length.ToString());
        Response.BinaryWrite(ms.ToArray());
        Response.Flush();
        ms.Close();
        ms.Dispose();
    }
    else
        Response.Write("Error!Connot Download");
}

我有二进制流而不是ms-excel文件。

PS：我真的想知道如何生成一个文件供下载，也就是说，为什么你的代码有效，浏览器会生成文件还是服务器？

Answer 1

NPOI是一个帮助模块，用于创建四个excel文件。这是在服务器端和内存中创建的。（ workbook.Write（ms）在内存中写入excel文件）excel文件以字节[]的形式通过网络传输，浏览器根据文件和内容类型决定如何处理它。

当你使用经典的asp.net时，在你的aspx页面中添加一个链接，如下所示

<a target="_blank" href="Handler.ashx" >download...</a>

创建一个Handler.ashx并将CodeExcel的代码放入Handler.ashx的ProcessRequest中。

public void ProcessRequest (HttpContext context)
{
    //create dumy data, or in youre case the data form somewhere else
    DataTable table = new DataTable();
    table.Columns.AddRange(new[]
        {
            new DataColumn("Name")
        });
    table.Rows.Add("david");
    table.Rows.Add("Ruud");

    // your code
    Stream s = RenderDataTableToExcel(dt);
    if (s != null)
    {
        MemoryStream ms = s as MemoryStream;
        Response.AddHeader("Content-Disposition", string.Format("attachment;filename=" + HttpUtility.UrlEncode(reportName) + DateTime.Now.ToString("yyyyMMdd") + ".xlsx"));
        Response.ContentType = "application/vnd.ms-excel";
        Response.AddHeader("Content-Length", ms.ToArray().Length.ToString());
        Response.BinaryWrite(ms.ToArray());
        Response.Flush();
        ms.Close();
        ms.Dispose();
    }
    else
        Response.Write("Error!Connot Download");
    }
}

在MVC中如下所示。

[HttpGet]
public ActionResult ExportToExcel(string reportName)
{
    byte [] reportDocument = RenderDataTableToExcel().ToArray();

    Response.StatusCode = (int)HttpStatusCode.OK;
    return File(reportDocument, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", reportName);
}

Answer 2

我使用过ajax TVT。

window.location.href = "?action=DownloadAll";
    //$.ajax({
    //    url: "?action=DownloadAll",
    //    type: "get",
    //    success: function () { }
    //});

Answer 3

您可以使用一些非常易读的代码将DataTable转换为Excel工作表：

XLWorkbook wb = new XLWorkbook();
DataTable dt = GetDataTableOrWhatever();
wb.Worksheets.Add(dt,"WorksheetName");

它也会跑得超快！

如何将DataTable变量导出到EXCEL并下载excel

3 个答案: