在 pictureBox 的Paint事件中写下如下代码
private  void pictureBox1_Paint(object sender, PaintEventArgs e)
        {
            foreach (Control C in this.Controls)
            {
                if (C is Label)
                {
                    Label L = (Label)C;
                   L.Visible = false;
                    e.Graphics.DrawString(L.Text, L.Font, new
          SolidBrush(L.ForeColor), L.Left - pictureBox1.Left, L.Top - pictureBox1.Top);
                }
            }
        }
或者在载入页面的时候在LOAD中写入下面代码：
pictureBox1.SendToBack();
            label1.BackColor = Color.Transparent;
            label1.Parent = pictureBox1;
            label1.BringToFront();