写入 CSV，然后保存或编辑

Question

我有问题。我在运行时创建一个 CSV，然后让用户能够保存或打开它，但它对我没有任何作用，我做错了什么？有人可以帮我吗？

public void WriteToCSV(List<mifid2_vpc_monitored_detail_view> list, string filename)
    {
        string attachment = "attachment; filename=" + filename;

        HttpContext.Current.Response.Clear();
        HttpContext.Current.Response.ClearHeaders();
        HttpContext.Current.Response.ClearContent();
        HttpContext.Current.Response.AddHeader("content-disposition", attachment);
        HttpContext.Current.Response.ContentType = "text/csv";
        HttpContext.Current.Response.AddHeader("Pragma", "public");
        HttpContext.Current.Response.ContentEncoding = Encoding.UTF8;


        WriteHeader();
        StringBuilder csv = new StringBuilder();

        string _uti, _counterparty;
        DateTime _maturity, _date;
        decimal _volume;

        var newLine = "";

        for (int i = 0; i < list.Count; i++)
        {
            if (list[i].uti_cd == null) _uti = "-"; else _uti = list[i].uti_cd;
            if (list[i].namecounterparty == null) _counterparty = "-"; else _counterparty = list[i].namecounterparty;
            if (list[i].maturity == null) _maturity = DateTime.MinValue.Date; else _maturity = list[i].maturity;
            if (list[i].contract_volume == 0) _volume = 0; else _volume = list[i].contract_volume;
            if (list[i].evaluation_date == null) _date = DateTime.MinValue.Date; else _date = list[i].evaluation_date;

            newLine = string.Format("{0},{1},{2},{3},{4}", _uti, _counterparty, _maturity, _volume, _date);
            csv.AppendLine(newLine);
        }

        HttpContext.Current.Response.Write(csv.ToString());
        HttpContext.Current.Response.End();
    }

    private void WriteHeader()
    {
        string columnNames = "UTI code, Counterparty, Maturity, Volume, Evaluation Date";
        HttpContext.Current.Response.Write(columnNames);
        HttpContext.Current.Response.Write(Environment.NewLine);
    }

Answer 1

代码对我来说很好用。但是浏览器下载的文件没有扩展名。

filename 是否包含文件扩展名？

如果不行，试试这个

string attachment = "attachment; filename=" + filename + ".csv";

Answer 2

我仍然不明白问题可能出在哪里，我尝试了不同的解决方案，然后我在网上找到了一个通过演示工作的示例，但是一旦我实施它，它就不起作用了，可能是我使用 sharepoint 2013 并且引用导出的按钮位于 webpart 中？

代码：

HttpResponse Response = HttpContext.Current.Response;

string csv = string.Empty;
csv += "UTI code, Counterparty, Maturity, Volume, Evaluation Date";
csv += "\r\n";

string _uti, _counterparty;
DateTime _maturity, _date;
decimal _volume;

for (int i = 0; i < list.Count; i++)
        {
            if (list[i].uti_cd == null) _uti = "-"; else _uti = list[i].uti_cd;
            if (list[i].namecounterparty == null) _counterparty = "-"; else _counterparty = list[i].namecounterparty;
            if (list[i].maturity == null) _maturity = DateTime.MinValue.Date; else _maturity = list[i].maturity;
            if (list[i].contract_volume == 0) _volume = 0; else _volume = list[i].contract_volume;
            if (list[i].evaluation_date == null) _date = DateTime.MinValue.Date; else _date = list[i].evaluation_date;
            csv += _uti + ",";
            csv += _counterparty + ",";
            csv += _maturity + ",";
            csv += _volume + ",";
            csv += _date;
            csv += "\r\n";
        }

        Response.Clear();
        Response.Buffer = true;
        Response.AddHeader("content-disposition", "attachment;filename=SqlExport.csv");
        Response.Charset = "";
        Response.ContentType = "application/text";
        Response.Output.Write(csv);
        Response.Flush();
        Response.End();

Answer 3

这应该会有所帮助：

public void WriteToCSV(List<mifid2_vpc_monitored_detail_view> list, string filename)
    {
    string attachment = "attachment; filename=" + filename;

    HttpContext.Current.Response.Clear();
    HttpContext.Current.Response.ClearHeaders();
    HttpContext.Current.Response.ClearContent();
    HttpContext.Current.Response.AddHeader("content-disposition", attachment);
    HttpContext.Current.Response.ContentType = "text/csv";
    HttpContext.Current.Response.AddHeader("Pragma", "public");
    HttpContext.Current.Response.ContentEncoding = Encoding.UTF8;


    WriteHeader();
    StringBuilder csv = new StringBuilder();

    string _uti, _counterparty;
    DateTime _maturity, _date;
    decimal _volume;

    var newLine = "";

    for (int i = 0; i < list.Count; i++)
    {
        if (list[i].uti_cd == null) _uti = "-"; else _uti = list[i].uti_cd;
        if (list[i].namecounterparty == null) _counterparty = "-"; else _counterparty = list[i].namecounterparty;
        if (list[i].maturity == null) _maturity = DateTime.MinValue.Date; else _maturity = list[i].maturity;
        if (list[i].contract_volume == 0) _volume = 0; else _volume = list[i].contract_volume;
        if (list[i].evaluation_date == null) _date = DateTime.MinValue.Date; else _date = list[i].evaluation_date;

        newLine = string.Format("{0},{1},{2},{3},{4}", _uti, _counterparty, _maturity, _volume, _date);
        csv.AppendLine(newLine);
    }


    MemoryStream mstream = new MemoryStream();
    StreamWriter sw = new StreamWriter(mstream);
    sw.Write(csv);
    sw.Flush();
    sw.Close();
    byte[] byteArray = mstream.ToArray();
    mstream.Flush();
    mstream.Close();
    HttpContext.Current.Response.BinaryWrite(byteArray);
    HttpContext.Current.Response.End();
}