如何移动和调整表格大小而没有边框？

允许移动和调整表单大小的一些示例代码：

  public partial class Form1 : Form {    public Form1() {      InitializeComponent();      this.FormBorderStyle = FormBorderStyle.None;      this.DoubleBuffered = true;      this.SetStyle(ControlStyles.ResizeRedraw, true);    }    private const int cGrip = 16;      // Grip size    private const int cCaption = 32;   // Caption bar height;    protected override void onPaint(PaintEventArgs e) {      Rectangle rc = new Rectangle(this.ClientSize.Width - cGrip, this.ClientSize.Height - cGrip, cGrip, cGrip);      ControlPaint.DrawSizeGrip(e.Graphics, this.BackColor, rc);      rc = new Rectangle(0, 0, this.ClientSize.Width, cCaption);      e.Graphics.FillRectangle(Brushes.DarkBlue, rc);    }    protected override void WndProc(ref Message m) {      if (m.Msg == 0x84) {  // Trap WM_NCHITTEST        Point pos = new Point(m.LParam.ToInt32());        pos = this.PointToClient(pos);        if (pos.Y < cCaption) {          m.Result = (IntPtr)2;  // HTCAPTION          return;        }        if (pos.X >= this.ClientSize.Width - cGrip && pos.Y >= this.ClientSize.Height - cGrip) {          m.Result = (IntPtr)17; // HTBOTTOMRIGHT          return;        }      }      base.WndProc(ref m);    }  }