private void TextBox_KeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.Enter)
{
GetCommand(txt_cmd.Text);
txt_cmd.Text = "";
}
else if (e.Key == Key.Up)
{
txt_cmd.Text = history.Peek(true);
}
else if (e.Key == Key.Down)
{
txt_cmd.Text = history.Peek(false);
}
}
