using System;using System.Drawing;using System.Windows.Forms;namespace WindowsFormsapplication2{    public partial class ang : Form    {        bool isMove = false;        PRivate Rectangle m_Rect;        private Point m_LastMSPoint;        public ang()        {            InitializeComponent();            DoubleBuffered = true;            this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer | ControlStyles.UserPaint, true);            m_Rect = new Rectangle(10, 10, 50, 30);        }        protected override void OnPaint(PaintEventArgs e)        {            e.Graphics.FillRectangle(SystemBrushes.ControlDark, this.m_Rect);            e.Graphics.DrawRectangle(SystemPens.ControlDarkDark, this.m_Rect);            //Rectangle r = e.ClipRectangle;            //this.label1.Text = r.X + "," + r.Y;        }        protected override void OnMouseDown(MouseEventArgs e)        {            base.OnMouseDown(e);            if (m_Rect.Contains(e.Location))            {                this.m_LastMSPoint = e.Location;                isMove = true;//注意要加在這里                Cursor = Cursors.SizeAll;            }            else            {                return;            }        }        protected override void OnMouseMove(MouseEventArgs e)        {            base.OnMouseMove(e);            if (e.Button != MouseButtons.Left)            {                return;            }            if (isMove == true)            {                this.label1.Text = m_LastMSPoint.X + "," + m_LastMSPoint.Y + " ; " + e.Location.X + "," + e.Location.Y;                this.m_Rect.Offset(e.Location.X - this.m_LastMSPoint.X, e.Location.Y - this.m_LastMSPoint.Y);                this.Invalidate();                this.m_LastMSPoint = e.Location;            }        }        protected override void OnMouseUp(MouseEventArgs e)        {            isMove = false;            Cursor = Cursors.Default;        }    }}