使用DataSource从ListBox中删除项目

Question

I have a listbox whose DataSource is a List who contains folders name. I want delete the folders from listbox and the path, but the first it doesn't work.

Here the code:

private static List<string> themesF;

 public Form1()
        {
            InitializeComponent();

 List<string> dirs = new List<string (System.IO.Directory.GetDirectories(@"Thems"));
var pngs = System.IO.Directory.GetFiles(@"Thems").Where(s => s.EndsWith(".png"));
            themesF = new List<string>();

            for (int i = 0; i < dirs.Count; i++)
            {
                themesF.Add(dirs[i].Substring(6));
                Console.WriteLine("A) Directorio " + dirs[i]);
                Console.WriteLine("B) Carpeta" + themesF[i]);
            }
            lb.DataSource = themesF;
            pbx.ImageLocation = (@"Thems\" + themesF[0] + @"\Preview.png");

        }
private void btnRemove_Click(object sender, EventArgs e)
    {
        String folder = lb.SelectedItem.ToString();
        themesF.Remove(folder);
        lb.DataSource = null;
        lb.DataSource = themesF;
        System.IO.Directory.Delete(@"Thems\" + folder,true);

    }

Answer 1

Try this :

private void btnRemove_Click(object sender, EventArgs e)
{
    string folder = themesF.Find(t=> t.Equals(lb.SelectedItem.Text));
    themesF.Remove(folder);
    lb.DataSource = themesF;
    System.IO.Directory.Delete(@"Thems\" + folder,true);

}

When you want to delete something from list, one way is find it first. And when you write this : lb.DataSource = something; You don't need to put null there first.

Answer 2

List<T> doesn't report changes to the list, so try using a BindingList<T> instead:

BindingList<string> themesF = new BindingList<string>();

Remove those DataSource lines from the Remove_Click event since those won't be necessary anymore. Just set the DataSource once.