abc

private void btnReadFileText_Click(object sender, EventArgs e)
{
    lstImgExport.Clear();
    OpenFileDialog ofd = new OpenFileDialog();
    if (ofd.ShowDialog() == DialogResult.OK)
    {
        string s = File.ReadAllText(ofd.FileName);
        txtListKeyword.Text = s;
        lstTextFromFile = new List<string>();

        // Use using StreamReader for disposing.
        using (StreamReader r = new StreamReader(ofd.FileName))
        {
            // Use while != null pattern for loop
            string line;
            while ((line = r.ReadLine()) != null)
            {
                lstTextFromFile.Add(line);
                lstTextFromFileSplit = line.Split('-').ToList();
            }
        }
    }
    else
        return;