private void pictureBox1_Paint(object sender, PaintEventArgs e)
        {
            if (((Control)sender).Tag != null)
                e.Graphics.DrawString("ssssssss",this.Font,Brushes.Red,0,20);

        }
        private void pictureBox1_MouseEnter(object sender, EventArgs e)
        {
            ((Control)sender).Tag = 1;
            ((Control)sender).Invalidate();
        }

        private void pictureBox1_MouseLeave(object sender, EventArgs e)
        {
            ((Control)sender).Tag = null;
            ((Control)sender).Invalidate();
        }