使用 MVC、C# 和 jQuery 导出到 CSV

Question

我正在尝试将列表导出到 CSV 文件。 我已经完成了所有工作，直到我想将文件写入响应流。这没有任何作用。

这是我的代码：

从页面调用该方法。

$('#btn_export').click(function () {
         $.post('NewsLetter/Export');
});

控制器中的代码如下：

[HttpPost]
        public void Export()
        {
            try
            {
                var filter = Session[FilterSessionKey] != null ? Session[FilterSessionKey] as SubscriberFilter : new SubscriberFilter();

                var predicate = _subscriberService.BuildPredicate(filter);
                var compiledPredicate = predicate.Compile();
                var filterRecords = _subscriberService.GetSubscribersInGroup().Where(x => !x.IsDeleted).AsEnumerable().Where(compiledPredicate).GroupBy(s => s.Subscriber.EmailAddress).OrderBy(x => x.Key);

                ExportAsCSV(filterRecords);
            }
            catch (Exception exception)
            {
                Logger.WriteLog(LogLevel.Error, exception);
            }
        }

        private void ExportAsCSV(IEnumerable<IGrouping<String, SubscriberInGroup>> filterRecords)
        {
            var sw = new StringWriter();
            //write the header
            sw.WriteLine(String.Format("{0},{1},{2},{3}", CMSMessages.EmailAddress, CMSMessages.Gender, CMSMessages.FirstName, CMSMessages.LastName));

            //write every subscriber to the file
            var resourceManager = new ResourceManager(typeof(CMSMessages));
            foreach (var record in filterRecords.Select(x => x.First().Subscriber))
            {
                sw.WriteLine(String.Format("{0},{1},{2},{3}", record.EmailAddress, record.Gender.HasValue ? resourceManager.GetString(record.Gender.ToString()) : "", record.FirstName, record.LastName));
            }

            Response.Clear();
            Response.AddHeader("Content-Disposition", "attachment; filename=adressenbestand.csv");
            Response.ContentType = "text/csv";
            Response.Write(sw);
            Response.End();
        }

但是在Response.Write(sw)之后什么也没有发生。是否可以通过这种方式保存文件？

问候

编辑
单击按钮时我看到的响应标头是：

HTTP/1.1 200 OK
Cache-Control: private
Content-Type: text/csv; charset=utf-8
Server: Microsoft-IIS/7.5
X-AspNetMvc-Version: 2.0
Content-Disposition: attachment; filename=adressenbestand.csv
X-Powered-By: ASP.NET
Date: Wed, 12 Jan 2011 13:05:42 GMT
Content-Length: 113

这对我来说似乎没问题..

编辑
我摆脱了 jQuery 部分，用超链接替换它，现在这对我来说工作正常：

<a class="export" href="NewsLetter/Export">exporteren</a>

Answer 1

yan.kun 走在正确的轨道上，但这要容易得多。

    public FileContentResult DownloadCSV()
    {
        string csv = "Charlie, Chaplin, Chuckles";
        return File(new System.Text.UTF8Encoding().GetBytes(csv), "text/csv", "Report123.csv");
    }

Answer 2

使用 MVC，您可以简单地返回如下文件：

public ActionResult ExportData()
{
    System.IO.FileInfo exportFile = //create your ExportFile
    return File(exportFile.FullName, "text/csv", string.Format("Export-{0}.csv", DateTime.Now.ToString("yyyyMMdd-HHmmss")));
}

Answer 3

除了 Biff MaGriff 的回答。要使用 JQuery 导出文件，请将用户重定向到新页面。

$('#btn_export').click(function () {
    window.location.href = 'NewsLetter/Export';
});

Answer 4

如果去掉字符串编写器会发生什么：

        Response.Clear();
        Response.AddHeader("Content-Disposition", "attachment; filename=adressenbestand.csv");
        Response.ContentType = "text/csv";
        //write the header
        Response.Write(String.Format("{0},{1},{2},{3}", CMSMessages.EmailAddress, CMSMessages.Gender, CMSMessages.FirstName, CMSMessages.LastName));

        //write every subscriber to the file
        var resourceManager = new ResourceManager(typeof(CMSMessages));
        foreach (var record in filterRecords.Select(x => x.First().Subscriber))
        {
            Response.Write(String.Format("{0},{1},{2},{3}", record.EmailAddress, record.Gender.HasValue ? resourceManager.GetString(record.Gender.ToString()) : "", record.FirstName, record.LastName));
        }

        Response.End();

Answer 5

尊敬的 Biff，这里有一些调整，让我可以使用该方法从 jQuery/Post 向服务器弹回 CSV，并作为 CSV 提示返回给用户。

    [Themed(false)]
    public FileContentResult DownloadCSV()
    {

        var csvStringData = new StreamReader(Request.InputStream).ReadToEnd();

        csvStringData = Uri.UnescapeDataString(csvStringData.Replace("mydata=", ""));

        return File(new System.Text.UTF8Encoding().GetBytes(csvStringData), "text/csv", "report.csv");
    }

如果您从具有如下代码的表单中点击此行，则需要 unescape 行，

    var input = $("<input>").attr("type", "hidden").attr("name", "mydata").val(data);
    $('#downloadForm').append($(input));
    $("#downloadForm").submit();

Answer 6

从视图中的按钮调用 .click（调用一些 java 脚本）。从那里通过 window.location.href = 'Controller/Method' 调用控制器方法；

在控制器中，要么执行数据库调用并获取数据表，要么调用某种方法将数据从数据库表获取到数据表，然后执行以下操作，

using (DataTable dt = new DataTable())
                        {
                            sda.Fill(dt);
                            //Build the CSV file data as a Comma separated string.
                            string csv = string.Empty;
                            foreach (DataColumn column in dt.Columns)
                            {
                                //Add the Header row for CSV file.
                                csv += column.ColumnName + ',';
                            }
                            //Add new line.
                            csv += "\r\n";
                            foreach (DataRow row in dt.Rows)
                            {
                                foreach (DataColumn column in dt.Columns)
                                {
                                    //Add the Data rows.
                                    csv += row[column.ColumnName].ToString().Replace(",", ";") + ',';
                                }
                                //Add new line.
                                csv += "\r\n";
                             }
                             //Download the CSV file.
                             Response.Clear();
                             Response.Buffer = true;
                             Response.AddHeader("content-disposition", "attachment;filename=SqlExport"+DateTime.Now+".csv");
                             Response.Charset = "";
                             //Response.ContentType = "application/text";
                             Response.ContentType = "application/x-msexcel";
                             Response.Output.Write(csv);
                             Response.Flush();
                             Response.End();
                           }

Answer 7

即使您已经解决了问题，这里还有另一种尝试使用 mvc 导出 csv。

return new FileStreamResult(fileStream, "text/csv") { FileDownloadName = fileDownloadName };

Answer 8

我认为您忘记使用

  Response.Flush();

下面的内容

  Response.Write(sw);

，请检查