Question

How do I code the whole list into the text file with commas in between each bit of data? Currently it is creating the file newData, but it is not putting in the variables from the list. Here is what I have so far.

public partial class Form1 : Form {
  List<string> newData = new List<string>();
}

Above is where I create my list. Below is where I am reading it from.

private void saveToolStripMenuItem_Click(object sender, EventArgs e) {
  TextWriter tw = new StreamWriter("NewData.txt");
  tw.WriteLine(newData);
  buttonSave.Enabled = true;
  textBoxLatitude.Enabled = false;
  textBoxLongtitude.Enabled = false;
  textBoxElevation.Enabled = false;
}

And below is where the variables are coming from.

private void buttonSave_Click(object sender, EventArgs e) {
  newData.Add (textBoxLatitude.Text);
  newData.Add (textBoxLongtitude.Text);
  newData.Add (textBoxElevation.Text);
  textBoxLatitude.Text = null;
  textBoxLongtitude.Text = null;
  textBoxElevation.Text = null;
}

Answer 1

 private void saveToolStripMenuItem_Click(object sender, EventArgs e)
    {

        TextWriter tw = new StreamWriter("NewData.txt");                       
        tw.WriteLine(String.Join(", ", newData));

        // Add appropriate error detection
    }

In response to the discussion in both main answer threads, here is an example from my older code of a more robust way to handle CSV output:

The above not checked for syntax, but the key concept is String.Join.

 public const string Quote = "\"";

 public static void EmitCsvLine(TextWriter report, IList<string> values)
    {
        List<string> csv = new List<string>(values.Count);

        for (var z = 0; z < values.Count; z += 1)
        {
            csv.Add(Quote + values[z].Replace(Quote, Quote + Quote) + Quote);
        }

        string line = String.Join(",", csv);

        report.WriteLine(line);
    }

This could be made slightly more general with an IEnumerable<object> but in the code I took this form, I didn’t have the need to.