在C＃表单上绘制的线太长

Question

I haven't seen any posts relating to this but a line drawn on my form is supposed to stop 5px before the boarder around the form but it doesn't. The purpose of this line is to separate two different user controls on one form if need be.

    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);
        if (optionalSecondPanel != null)
        {
            Graphics g;

            g = e.Graphics;

            Pen myPen = new System.Drawing.Pen(System.Drawing.Color.Black);
            g.DrawLine(myPen, mainPanel.Width + 5, btnPannel.Bottom + 5, mainPanel.Width + 5, this.Height - 5);
            myPen.Dispose();
            g.Dispose();
        }
    }

However when drawn on the screen the line separating the user controls goes all the way to the bottom of the form. It doesn't stop when it is supposed to.

Answer 1

g.DrawLine(myPen, mainPanel.Width + 5, btnPannel.Bottom - 5, mainPanel.Width + 5, this.Height - 5);

我相信.Bottom增加会下降，因此，如果减去5，它应该会增加该条的底部。