如何从列表保存内容 <string> 到C＃中的文本文件？

Question

I have a listbox that displays the names of the files that are opened either with a dragDrop functionality or with an OpenFileDialog, the file paths are stored in the List named playlist, and the listbox only displays the names without paths and extensions. When my form closes, the playlist content is saved to a .txt file. When I open again my application, the content in the text file is stored again in the listbox and the playlist. But when I add new files after re-opening the form, I don't know why it leaves a blank line between the last files and the recently added ones.

This is the code I use to WRITE the content of playlist(List) in the txt file:

 private void Form1_FormClosed(object sender, FormClosedEventArgs e)
    {
        if(listBox1.Items.Count > 0)
        {
            StreamWriter str = new StreamWriter(Application.StartupPath + "/Text.txt");
            foreach (String s in playlist)
            {
                str.WriteLine(s);
            }
            str.Close();
        }

This is the code used to READ the same txt file:

 private void Form1_Load(object sender, EventArgs e) //Form Load!!!
    {
        FileInfo info = new FileInfo(Application.StartupPath + "/Text.txt");
        if(info.Exists)
        {
            if (info.Length > 0)
            {
                System.IO.StreamReader reader = new System.IO.StreamReader(Application.StartupPath + "/Text.txt"); //StreamREADER
                try
                {
                    do
                    {
                        string currentRead = reader.ReadLine();
                        playlist.Add(currentRead);
                        listBox1.Items.Add(System.IO.Path.GetFileNameWithoutExtension(currentRead));

                    } while (true);
                }
                catch (Exception)
                {
                    reader.Close();
                    listBox1.SelectedIndex = 0;
                }
            }
            else
            {
                File.Delete(Application.StartupPath + "/Text.txt");
            }
        }
        else
        {
            return;
        }

    }

The code used to add files to listbox and playlist:

OpenFileDialog ofd = new OpenFileDialog();
        ofd.Title = "Select File(s)";
        ofd.Filter = "Audio Files (*.mp3, *.wav, *.wma)|*.mp3|*.wav|*.wma";
        ofd.InitialDirectory = "C:/";
        ofd.RestoreDirectory = false;
        ofd.Multiselect = true;
        ofd.ShowDialog();

        foreach (string s in ofd.FileNames)
        {
            listBox1.Items.Add(Path.GetFileNameWithoutExtension(s));
            playlist.Add(s);
        }


        listBox1.SelectedIndex = 0;

This is what I get when I add new files after re-opening my form:

Thanks in advance, I hope StackOverflow community can help me!

Answer 1

First of all: debug your code and you'll find the problem yourself :)

Issue is the use of the WriteLine method. The last line you write should use the Write method instead so that you don't have an empty line at the end. Alternatively and easier to implement is to only add non-empty lines to your playlist such like this:

// ...
do
{
    string currentRead = reader.ReadLine();
    if (!string.IsNullOrWhiteSpace(currentRead)) // ignore empty lines
    {
        playlist.Add(currentRead);
       listBox1.Items.Add(System.IO.Path.GetFileNameWithoutExtension(currentRead));
    }
} while (true);

As a side comment: while (true) and using exception handling is a bad approach to end a loop.