1.在private添加
 procedure ComponentControl(Control: TControl; Shift: TShiftState;
       X,Y,Precision: integer);
2.添加代码
procedure TForm1.ComponentControl(Control: TControl; Shift: TShiftState;
  X, Y, Precision: integer);
var
  SC_MANIPULATE: Word;
begin
  if (X<=Precision) and (Y>Precision) and (Y<Control.Height-Precision) then
    begin
    SC_MANIPULATE := $F001;
    Control.Cursor   :=   crSizeWE;
    end
  else if (X>=Control.Width-Precision) and (Y>Precision) and (Y<Control.Height-Precision) then
    begin
    SC_MANIPULATE :=   $F002;
    Control.Cursor   :=   crSizeWE;
    end
  else if (X>Precision) and (X<Control.Width-Precision) and (Y<=Precision) then
    begin
    SC_MANIPULATE := $F003;
    Control.Cursor := crSizeNS;
    end
  else if (X<=Precision) and (Y<=Precision) then
    begin
    SC_MANIPULATE := $F004;
    Control.Cursor   :=   crSizeNWSE;
    end
   else if (X>=Control.Width-Precision) and (Y<=Precision) then
     begin
     SC_MANIPULATE     :=   $F005;
     Control.Cursor   :=   crSizeNESW         ;
     end
   else if (X>Precision) and (X<Control.Width-Precision) and (Y>=Control.Height-Precision) then
     begin
     SC_MANIPULATE := $F006;
     Control.Cursor   :=   crSizeNS;
     end
   else if (X<=Precision) and (Y>=Control.Height-Precision) then
     begin
     SC_MANIPULATE     :=   $F007;
     Control.Cursor   :=   crSizeNESW;
     end
  else if (X>=Control.Width-Precision) and (Y>=Control.Height-Precision) then
    begin
    SC_MANIPULATE := $F008;
    Control.Cursor := crSizeNWSE;
    end
  else if (X>5) and (Y>5) and (X<Control.Width-5) and (Y<Control.Height-5) then
    begin
    SC_MANIPULATE := $F009;
    Control.Cursor :=  crSizeAll;
    end
  else
    begin
    SC_MANIPULATE   :=   $F000;
    Control.Cursor   :=   crDefault;
    end;
 if Shift=[ssLeft]   then
    begin
    ReleaseCapture;               //释放鼠标的捕获功能，使之能得到所有鼠标输入！
    Control.Perform(WM_SYSCOMMAND, SC_MANIPULATE, 0);
    end;
end;
3.在需要拖动或改变大小的控件的OnMouseMove:
  ComponentControl((Sender as TControl),   Shift,   X,   Y,   10);