C#: System.ObjectDisposedException: 'Cannot write to a closed TextWriter.'

I’m writing a program that exports data from a DataTable into a csv file but when I run the program I get the error : System.ObjectDisposedException: ‘Cannot write to a closed TextWriter.’

Here’s the code:

 StreamWriter sw = new StreamWriter("CMS.csv", true);

            do
            {
                // Headers
                for (int i = 0; i < dt.Columns.Count; i++)
                {
                    sw.Write(dt.Columns[i]);
                    if (i < dt.Columns.Count - 1)
                    {
                        sw.Write(",");
                    }
                }
                sw.Write(sw.NewLine);

                // Rows
                foreach (DataRow dr in dt.Rows)
                {
                    for (int i = 0; i < dt.Columns.Count; i++)
                    {
                        if (!Convert.IsDBNull(dr[i]))
                        {
                            string value = dr[i].ToString();
                            if (value.Contains(','))
                            {
                                value = String.Format("\"{0}\"", value);
                                sw.Write(value);
                            }
                            else
                            {
                                sw.Write(dr[i].ToString());
                            }
                        }
                        if (i < dt.Columns.Count - 1)
                        {
                            sw.Write(",");
                        }
                    }
                    sw.Write(sw.NewLine);
                }

                sw.Close();
            } while (dt.Rows.Count != 0);
        }

>Solution :

You need to move the call to sw.Close(); to be outside of the do/while loop.

Better yet, recommend that you use ‘using’ instead.

using (StreamWriter sw = new StreamWriter("CMS.csv", true)) {
   ... the do/while loop
}

that way, using will always take care of closing the stream, even if an exception happens.