Текст на PictureBox стирается при сворачивании-разворачивании окна

PictureBox[] vichisl = new PictureBox[30];
 
private void button1_Click(object sender, EventArgs e)
        {
            vichisl[i] = new PictureBox(); 
            vichisl[i].Location = new System.Drawing.Point(100, 100);
            vichisl[i].Size = new System.Drawing.Size(150, 84);
            vichisl[i].Image = new Bitmap("image/vichesl_box.png");
            vichisl[i].MouseDown += new System.Windows.Forms.MouseEventHandler(this.Vichisl_MouseDown);
            vichisl[i].MouseMove += new System.Windows.Forms.MouseEventHandler(this.Vichisl_MouseMove);
            vichisl[i].MouseUp += new System.Windows.Forms.MouseEventHandler(this.Vichisl_MouseUp);
            vichisl[i].Paint += new System.Windows.Forms.PaintEventHandler(this.Paint_text);
            vichisl[i].MouseClick += new System.Windows.Forms.MouseEventHandler(this.Right_MouseClick);
 
            Controls.Add(vichisl[i]);
 
            i++;
        }

private void Paint_text(object sender, System.Windows.Forms.PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            g.DrawString(textBox1.Text, new Font("Arial", 10), System.Drawing.Brushes.Blue, new Point(30, 30));
 
            textBox1.Text = String.Empty;
        }

this.Resize += delegate
{
    pictureBox1.Invalidate();
};