... " " + this.pictureBox1.Height; if (filedangmo) { this.Text = openFileDialog1.FileName; lenh = "play mediafile"; mciSendString(lenh, null, 0, IntPtr.Zero); this.pictureBox2.Visible = true; } else ... private void button3_Click(object sender, EventArgs e) { if(trangthai().Equals("stopper")){ lenh = "play mediafile"; mciSendString(lenh, null, 0, IntPtr.Zero); }else { lenh = "stop mediafile"; mciSendString(lenh, ... void hamfullscreen() { lenh = "stop mediafile"; mciSendString(lenh, null, 0, IntPtr.Zero); lenh = "play mediafile fullscreen"; mciSendString(lenh, null, 0, IntPtr.Zero); } private void chạyToolStripMenuItem_Click(object...