鼠标输入/离开消息不起作用?

时间:2012-05-29 07:36:19

标签: delphi custom-controls mouseevent delphi-xe2 windows-messages

我正在尝试检测鼠标进入/离开消息CM_MOUSEENTERCM_MOUSELEAVE,但它没有抓住它。我在这里做错了什么?

type
  TMyControl = class(TCustomControl)
  private
    procedure CMMouseEnter(var Message: TMessage); message CM_MOUSEENTER;
    procedure CMMouseLeave(var Message: TMessage); message CM_MOUSELEAVE;
    procedure WMNCHitTest(var Message: TWMNCHitTest); message WM_NCHITTEST;
  end;

procedure TMyControl.CMMouseEnter(var Message: TMessage);
begin
  //Handle mouse entering
  //Breakpoint never reached, procedure never called
end;

procedure TMyControl.CMMouseLeave(var Message: TMessage);
begin
  //Handle mouse leaving
  //Breakpoint never reached, procedure never called
end;

procedure TMyControl.WMNCHitTest(var Message: TWMNCHitTest);
var
  Ch: Bool;
begin
  if csDesigning in ComponentState then
    Message.Result := HTCLIENT
  else begin
    Ch:= False;

    //Do checks and pass `Ch:= True;` if something changed...

    if Ch then Invalidate;
  end;
end;

1 个答案:

答案 0 :(得分:7)

我想出了我的问题:我也在使用WM_NCHITTEST,我没有通过inherited;。我添加了这个,现在它工作正常。