这是播放器里的代码  谁帮我解释下
 private int num_ctl_banks = 1;
 private int num_ctl_lab_text = 0;
private void timer3_Tick(object sender, EventArgs e)
        {
            
                if (num_ctl_banks == 1)
                {
                    lab_mp3_name.Text = getBanks(num_ctl_lab_text) + axWindowsMediaPlayer1.currentMedia.name;
                    if (num_ctl_lab_text == 5)
                    {
                        num_ctl_banks = 2;
                        return;
                    }
                    num_ctl_lab_text++;
                }

                if (num_ctl_banks == 2)
                {
                    lab_mp3_name.Text = getBanks(num_ctl_lab_text)  + axWindowsMediaPlayer1.currentMedia.name;
                    if (num_ctl_lab_text == 0)
                    {

                        num_ctl_banks = 3;
                        return;
                    }
                    num_ctl_lab_text--;
                }

                if (num_ctl_banks == 3)
                {
                    lab_mp3_name.Text = axWindowsMediaPlayer1.currentMedia.name + getBanks(num_ctl_lab_text);
                    if (num_ctl_lab_text == 5)
                    {

                        num_ctl_banks = 4;
                        return;
                    }
                    num_ctl_lab_text++;
                }

                if (num_ctl_banks == 4)
                {
                    lab_mp3_name.Text =  axWindowsMediaPlayer1.currentMedia.name + getBanks(num_ctl_lab_text);
                    if (num_ctl_lab_text == 0)
                    {

                        num_ctl_banks = 1;
                        return;
                    }
                    num_ctl_lab_text--;
                }
           
        }