Перемещение объектов OvalShape по форме мышкой

 ovalShape.MouseDown += new MouseEventHandler(ovalShape_MouseDown);
            ovalShape.MouseUp += new MouseEventHandler(ovalShape_MouseUp);
            ovalShape.MouseMove += new MouseEventHandler(ovalShape_MouseMove);

void ovalShape_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                ovalShape.Tag = Control.MousePosition;
                ovalShape.Cursor = Cursors.SizeAll;
            }
        }
        void ovalShape_MouseUp(object sender, MouseEventArgs e)
        {
            ovalShape.Tag = null;
            ovalShape.Cursor = Cursors.Default;
        }
        void ovalShape_MouseMove(object sender, MouseEventArgs e)
        {
            OvalShape oval=sender as OvalShape;
            if (oval.Tag is Point && e.Button == MouseButtons.Left)
            {
                Point oldMousePosition = (Point)ovalShape.Tag;
                Point newMousePosition = Control.MousePosition;
                oval.Left += newMousePosition.X - oldMousePosition.X;
                oval.Top += newMousePosition.Y - oldMousePosition.Y;
                ovalShape.Tag = newMousePosition;
            }
        }

 using System;
using System.Drawing;
using System.Windows.Forms;
using Microsoft.VisualBasic.PowerPacks;
using System.Collections.Generic;
 
namespace WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        List<OvalShape> ovals = new List<OvalShape>();
        int i = 0;
        public Form1()
        {
            InitializeComponent();
        }
 
        private void Form1_Load(object sender, EventArgs e)
        {
 
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            Random rand = new Random();
            int temp1, temp2;
            temp1 = rand.Next(1, this.ClientSize.Width - 250);
            temp2 = rand.Next(1, this.ClientSize.Height - 100);
            i++;
            ShapeContainer canvas = new ShapeContainer();
            OvalShape oval = new OvalShape(temp1, temp2, 20, 20);
            oval.Name = "Oval" + i.ToString();
            oval.DoubleClick += oval_DoubleClick;
            ovals.Add(oval);
            canvas.Parent = this;
            oval.Parent = canvas;
        }
 
        void oval_DoubleClick(object sender, EventArgs e)
        {
            ovals.Remove((sender as OvalShape));
            (sender as OvalShape).Click -= oval_DoubleClick;
            (sender as OvalShape).Dispose();
        }
    }
}

using System;
using System.Drawing;
using System.Windows.Forms;
using Microsoft.VisualBasic.PowerPacks;
using System.Collections.Generic;
 
namespace WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        List<OvalShape> ovals = new List<OvalShape>();
        int i = 0;
        public Form1()
        {
            InitializeComponent();
        }
 
        private void Form1_Load(object sender, EventArgs e)
        {
 
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            Random rand = new Random();
            int temp1, temp2;
            temp1 = rand.Next(1, this.ClientSize.Width - 250);
            temp2 = rand.Next(1, this.ClientSize.Height - 100);
            i++;
            ShapeContainer canvas = new ShapeContainer();
            OvalShape oval = new OvalShape(temp1, temp2, 20, 20);
            oval.Name = "Oval" + i.ToString();
            oval.DoubleClick += oval_DoubleClick;
            oval.MouseDown += new MouseEventHandler(oval_MouseDown);
            oval.MouseUp += new MouseEventHandler(oval_MouseUp);
            oval.MouseMove += new MouseEventHandler(oval_MouseMove);
            ovals.Add(oval);
            canvas.Parent = this;
            oval.Parent = canvas;
        }
 
        void oval_DoubleClick(object sender, EventArgs e)
        {
OvalShape oval=sender as OvalShape;
            ovals.Remove(oval);
            oval.Click -= oval_DoubleClick;
            oval.MouseDown -= new MouseEventHandler(oval_MouseDown);
            oval.MouseUp -= new MouseEventHandler(oval_MouseUp);
            oval.MouseMove -= new MouseEventHandler(oval_MouseMove);
            oval.Dispose();
        }
void oval_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
            OvalShape oval=sender as OvalShape;
                oval.Tag = Control.MousePosition;
                oval.Cursor = Cursors.SizeAll;
            }
        }
        void oval_MouseUp(object sender, MouseEventArgs e)
        {
            OvalShape oval=sender as OvalShape;
            oval.Tag = null;
            oval.Cursor = Cursors.Default;
        }
        void oval_MouseMove(object sender, MouseEventArgs e)
        {
            OvalShape oval=sender as OvalShape;
            if (oval.Tag is Point && e.Button == MouseButtons.Left)
            {
                Point oldMousePosition = (Point)ovalShape.Tag;
                Point newMousePosition = Control.MousePosition;
                oval.Left += newMousePosition.X - oldMousePosition.X;
                oval.Top += newMousePosition.Y - oldMousePosition.Y;
                oval.Tag = newMousePosition;
            }
        }
    }
}

Point oldMousePosition = (Point)ovalShape.Tag;

Point oldMousePosition = (Point)oval.Tag;