[RESOLVED] [2.0] Analog clock?

[high6]

Always wanted to learn about cos/sin so I am trying to make an analog clock. The problem is more in the GDI+ then the actual clock. This is what I am using.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace Analog_Clock
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        const int HourLength = 100;
        const int MinuteLength = 150;
        const int SecondLength = 200;

        bool MyDisposed = false;
        
        void MyPaint()
        {
                Graphics maing = Graphics.FromHwnd(SafeGetHandle());

                Bitmap backbuffer = new Bitmap(this.Width, this.Height);
                Graphics g = Graphics.FromImage(backbuffer);

                float centerx = this.Width / 2;
                float centery = this.Height / 2;

                g.Clear(Color.Black);

                //Draw the hour hand
                int hour = DateTime.Now.Hour % 12;
                g.DrawLine(new Pen(Color.Red, 3), centerx, centery, centerx + (float)(HourLength * Degrees.Cos((hour * 30) - 90)), centery + (float)(HourLength * Degrees.Sin((hour * 30) - 90)));

                //Draw the minute hand
                int minute = DateTime.Now.Minute;
                g.DrawLine(new Pen(Color.Red, 2), centerx, centery, centerx + (float)(MinuteLength * Degrees.Cos((minute * 6) - 90)), centery + (float)(MinuteLength * Degrees.Sin((minute * 6) - 90)));

                //Draw the second hand
                int second = DateTime.Now.Second;
                g.DrawLine(new Pen(Color.Red, 1), centerx, centery, centerx + (float)(SecondLength * Degrees.Cos((second * 6) - 90)), centery + (float)(SecondLength * Degrees.Sin((second * 6) - 90)));

                //Draw the millisecond hand for fun
                int milli = DateTime.Now.Millisecond;
                g.DrawLine(new Pen(Color.Red, 1), centerx, centery, centerx + (float)(20 * Degrees.Cos((milli * .36) - 90)), centery + (float)(20 * Degrees.Sin((milli * .36) - 90)));

                

                maing.DrawImageUnscaled(backbuffer, 0, 0);
                
        }
        public IntPtr SafeGetHandle()
        {
            if (this.InvokeRequired)
                return (IntPtr)this.Invoke(new SafeGetHandleD(SafeGetHandle));
            return this.Handle;
        }
        public delegate IntPtr SafeGetHandleD();
        private void Form1_Load(object sender, EventArgs e)
        {
            System.Timers.Timer t = new System.Timers.Timer(10);
            t.Elapsed += new System.Timers.ElapsedEventHandler(t_Elapsed);
            t.Start();
        }

        void t_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            MyPaint();
        }

        private void Form1_Paint(object sender, PaintEventArgs e)
        {
            MyPaint();
        }
    }
}

How should I do the back buffer? Also the error is on

return (IntPtr)this.Invoke(new SafeGetHandleD(SafeGetHandle));

when I close the app.

I tried adding ifs about this.IsDisposed. But it is false when it gets called.