如何知道光标移出或移进控件（如：panel)？

Question

如何知道光标移出或移进控件（如：panel)？
用什么事件？

Answer 1

API :SetCapture 和ReleaseCapture 
用法去看MSDN包你满意！不满意去报警！

Answer 2

使用消息处理
procedure CMMouseEnter(var Message: TMessage); message CM_MOUSEENTER;／／移进
    procedure CMMouseLeave(var Message: TMessage); message CM_MOUSELEAVE;／／移出

Answer 3

procedure TForm1.Panel1MouseMove(Sender: TObject; Shift:TShiftState; X,  Y: Integer);
var
 a:TRect;
 b:TPoint;
begin
 a:=rect(0,0,panel1.Width+panel1.Left,panel1.Height+panel1.Top);
 b.X:=x;
 b.Y:=y;
 if PtInRect(a,b) then showmessage('光标移入');
end;

Answer 4

充分利用消息机制!方法一:继承并创建新类TNewPanel =class(TPanel)
private
  FOnMouseLeave: TNotifyEvent;
  FOnMouseEnter: TNotifyEvent;
  procedure CMMouseLeave(var Message: TMessage); message CM_MOUSELEAVE;
  procedure CMMouseEnter(var Message: TMessage); message CM_MOUSENTER;
public
  constructor Create(AOwner: TComponent);override;
published  
  property OnMouseLeave: TNotifyEvent read FOnMouseLeave write FOnMouseLeave;
  property OnMouseEnter: TNotifyEvent read FOnMouseEnter write FOnMouseEnter;
end;constructor TNewPanel.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
end;procedure TNewPanel.CMMouseLeave(var Message: TMessage);
begin
  inherited;
  if Assigned(FOnMouseLeave) then
    FOnMouseLeave(Self);
end;procedure TNewPanel.CMMouseEnter(var Message: TMessage);
begin
  inherited;
  if Assigned(FOnMouseEnter) then
    FOnMouseEnter(Self);
end;方法二:
procedure MouseWnd(var Message: TMessage);
begin
  Case Message.Msg of
    CM_MOUSENTER://移入时
    CM_MOUSELEAVE://移出时
  Panel.dispatch(Message);
end;创建窗体时:
Panel.WindowProc := MouseWnd;