OpenFileDialog openFileDialogModele = new OpenFileDialog();
            openFileDialogModele.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*";
            openFileDialogModele.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);
 
            DialogResult result = openFileDialogModele.ShowDialog();
            if (result == DialogResult.OK) 
            {
                textBoxModele.Text = openFileDialogModele.FileName;
            }

List<string> lines = new List<string>();
 
string line;
System.IO.StreamReader file = new System.IO.StreamReader(@"c:\test.txt");
while ((line = file.ReadLine()) != null)
{
   lines.Add(line);
}

System.IO.File.WriteAllText(@"C:\Users\Public\TestFolder\WriteText.txt", text);