如何从ASP.NETCore导出CSV文件

我正在尝试将代码从ASP.net迁移到ASP.net核心。

就像下面的ASP.net代码一样，

var progresses = db.Progresses.Where(p => p.UserId == id).Include(p => p.User.UserMetaData).Include(p => p.Quiz).Include(p => p.User.Groups).OrderByDescending(p => p.UpdatedAt).ToList();

List reportCSVModels = new List();
const string downloadName = "Reports.csv";
var csv = new CsvWriter(Response.Output);

csv.Configuration.RegisterClassMap();

Response.ClearContent();

Response.COntentType= "application/octet-stream";

Response.AddHeader("Content-Disposition",
   "attachment; filename=" + downloadName);

csv.WriteHeader();
foreach (var progress in progresses)
{
    var reportCSVModel = new ReportCSVModel();
    reportCSVModel.Quiz = progress.Quiz.Title;
    reportCSVModel.Score = (progress.CorrectAnswersCount * progress.PointsPerQuestion).ToString();
    reportCSVModel.Status = progress.Status;
    reportCSVModel.CompletedDate = progress.UpdatedAt.ToString();
    reportCSVModel.Location = progress.User.UserMetaData != null ? progress.User.UserMetaData.Location : "";
    reportCSVModel.Group = progress.User.Groups.FirstOrDefault() != null ? progress.User.Groups.FirstOrDefault().Name : "";

    csv.WriteRecord(reportCSVModel);
}
Response.Flush();
Response.End();
return null;

但是在ASP.NET核心中使用它时，我将其转换为

var progresses = _elearnContext.Progress.Where(p => p.UserId == id).Include(p => p.User.UserMetaData).Include(p => p.Quiz).Include(p => p.User.Groups).OrderByDescending(p => p.UpdatedAt).ToList();

// List reportCSVModels = new List();
List reportCSVModels = new List();
const string downloadName = "Reports.csv";

System.IO.TextWriter writeFile = new StreamWriter(Response.Body.ToString());
CsvWriter csv = new CsvWriter(writeFile);
csv.Configuration.RegisterClassMap();
Response.Clear();
Response.COntentType= "application/octet-stream";
Response.Headers.Add("Content-Disposition", "attachment; filename=" + downloadName);


csv.WriteHeader();
foreach (var progress in progresses)
{
    var reportCSVModel = new ReportCSVModel();
    reportCSVModel.Quiz = progress.Quiz.Title;
    reportCSVModel.Score = (progress.CorrectAnswersCount * progress.PointsPerQuestion).ToString();
    reportCSVModel.Status = progress.Status;
    reportCSVModel.CompletedDate = progress.UpdatedAt.ToString();
    reportCSVModel.Location = progress.User.UserMetaData != null ? progress.User.UserMetaData.Location : "";
    reportCSVModel.Group = progress.User.Groups.FirstOrDefault() != null ? progress.User.Groups.FirstOrDefault().Name : "";

    csv.WriteRecord(reportCSVModel);
}

Response.Clear();
return null;

在ASP.net中Response.Output可用，但在核心中不可用。所以我试图像Response.Body

谁能告诉我，我做错了什么？

考虑更改方法以更符合当前建议的语法。

构造CSV并返回FileResult，这使代码不必直接操纵Response对象。

[HttpGet]
public IActionResult MyExportAction() {
    var progresses = _elearnContext.Progress.Where(p => p.UserId == id)
        .Include(p => p.User.UserMetaData)
        .Include(p => p.Quiz)
        .Include(p => p.User.Groups)
        .OrderByDescending(p => p.UpdatedAt)
        .ToList()
        .Select(progress => 
            new ReportCSVModel() {
                Quiz = progress.Quiz.Title,
                Score = (progress.CorrectAnswersCount * progress.PointsPerQuestion).ToString(),
                Status = progress.Status,
                CompletedDate = progress.UpdatedAt.ToString(),
                Location = progress.User.UserMetaData != null ? progress.User.UserMetaData.Location : "",
                Group = progress.User.Groups.FirstOrDefault() != null ? progress.User.Groups.FirstOrDefault().Name : ""
            }
        );

    List reportCSVModels = progresses.ToList();

    var stream = new MemoryStream();
    var writeFile = new StreamWriter(stream);
    var csv = new CsvWriter(writeFile);
    csv.Configuration.RegisterClassMap();

    csv.WriteRecords(reportCSVModels);

    stream.Position = 0; //reset stream
    return File(stream, "application/octet-stream", "Reports.csv");
}