how to get all the data to CSV from memorystream?

Question

Below is my method to export data to CSV.

public MemoryStream ExportToCsv(string jsonData, HttpResponseBase response, string fileName)
{
    using (MemoryStream stream = new MemoryStream())
    {
        StreamWriter writer = new StreamWriter(stream);
        try
        {
            String s = JsonToCsv(jsonData, ",");
            writer.Write(s);
            stream.Position = 0;
        }
        catch (Exception ex)
        {
            clsErrorHandling.WriteLog("CSVExport", "GenerateStreamFromString", ex.Message);
            throw;
        }
        finally
        {
            writer.Flush();
            writer.Close();
            response.Clear();
            response.Buffer = true;
            response.ContentType = "application/csv";
            response.AddHeader("Content-Disposition", "attachment; filename=" + fileName + "");
            response.BinaryWrite(stream.ToArray());
        }

        return stream;
    }
}

#region Private CSV Block

private String JsonToCsv(string jsonData, string delimiter)
{
    try
    {
        using (StringWriter swObj = new StringWriter())
        {
            using (var csv = new CsvWriter(swObj))
            {
                csv.Configuration.SkipEmptyRecords = true;
                csv.Configuration.WillThrowOnMissingField = false;
                csv.Configuration.Delimiter = delimiter;

                using (var dt = jsonStringToTable(jsonData))
                {
                    foreach (DataColumn col in dt.Columns)
                    {
                        csv.WriteField(col.ColumnName);
                    }
                    csv.NextRecord();

                    foreach (DataRow row in dt.Rows)
                    {
                        for (var i = 0; i < dt.Columns.Count; i++)
                        {
                            csv.WriteField(row[i]);
                        }
                        csv.NextRecord();
                    }
                }

            }
            return swObj.ToString();
        }

    }
    catch (Exception ex)
    {
        clsErrorHandling.WriteLog("CSVExportHandler", "JsonToCsv", ex.Message);
        return null;
    }
}

private DataTable jsonStringToTable(string jsonContent)
{
    DataTable dt = JsonConvert.DeserializeObject<DataTable>(jsonContent);
    return dt;
}

#endregion

If the number of records is less than 100.Then no issue. But when the data is 100 or 150+ , last 15-20records are not written to the csv file.

Suppose if the number of records is 175, then I get in csv some around 163. If the number of records is 150 then I get in csv arounf 131 & so on.

What could be the causing this ? How should I handle this?

Answer 1

A number small updates in my public method fixed my issue.

public MemoryStream ExportToCsv(string jsonData, HttpResponseBase response, string fileName)
{
       using (MemoryStream stream = new MemoryStream())
        {
            StreamWriter writer = new StreamWriter(stream);
            try
            {
                response.Clear();
                response.Buffer = true;
                response.ContentType = "application/csv";
                response.AddHeader("Content-Disposition", "attachment; filename=" + fileName + "");
                String s = JsonToCsv(jsonData, ",");
                writer.Write(s);
                writer.Flush();

                stream.Position = 0;
                response.BinaryWrite(stream.ToArray());
            }
            catch (Exception ex)
            {

                throw;
            }
            finally
            {
                writer.Close();
            }
    return stream;
}

}

Hope this helps :)