相关疑难解决方法(0)

我的代码:

        private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
    {
        ngr.Dispose();
                    List<Image> list = new List<Image>();
        Graphics g = Graphics.FromImage(pictureBox1.Image);
        Brush redBrush = new SolidBrush(Color.Red);
        Pen pen = new Pen(redBrush,3);
        MessageBox.Show(pictureBox1.Image.Width + " " + pictureBox1.Image.Height);
        for (int i = 0; i < pictureBox1.Image.Width; i = (pictureBox1.Image.Width / 3) + i)
        {
            for (int y = 0; y < pictureBox1.Image.Height; y = (pictureBox1.Image.Height / 3) + y)
            {
                Rectangle r = new Rectangle(i, y, pictureBox1.Image.Width / 3, pictureBox1.Image.Height / 3);
                g.DrawRectangle(pen,r ); …