如何將DataTable變量導出到EXCEL並下載Excel

Question

我正在嘗試像這樣使用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");
}

我有二進制流而不是ms-excel文件。

PS：我真的很想知道如何生成要下載的文件，也就是說，為什么您的代碼有效，瀏覽器還是要生成文件或服務器？

Answer 1

NPOI是創建四個您的Excel文件的幫助器模塊。 這是在服務器端和內存中創建的。 （ workbook.Write（ms）將excel文件寫入內存中）excel文件作為字節[]通過網絡傳輸，瀏覽器根據文件和內容類型決定如何處理它。

當您使用經典的asp.net時，請在您的aspx頁面中放置一個鏈接，如下所示

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

創建一個Handler.ashx，並將DownloadExcel的代碼放入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

我用過ajax TVT。

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

Answer 3

您可以使用一些易讀的代碼將DataTable轉換為Excel工作表：

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

它也將超快運行！