如果鼠标不在VirtualTreeView(TVirtualStringTree)上，如何禁用MouseWheel [英] How to disable MouseWheel if mouse is not over VirtualTreeView (TVirtualStringTree)

问题描述

如果将TVirtualStringTree放在焦点上，则默认情况下其行为是正常的-即使鼠标不在控制之下(除非在另一个TVirtualStringTree之上)，它也会在鼠标滚轮上滚动.

TVirtualStringTree behaves by default if it is focused - it will scroll on mouse wheel even if mouse is not over control (except if it is over another TVirtualStringTree).

是否有一种快速而优雅的方法来禁用此行为?

Is there a quick and elegant way to disable this behaviour?

我已经使用OnMouseWheel事件进行了此操作，并通过PtInRect检查是否Mouse.CursorPos是否在控件上，但是我觉得有更好的方法可以执行此操作，因为这样我可以为我添加的每个TreeView定义一个新事件，并处理何时使控件集中/不集中，因此我希望必须有更好的方法来禁用它.

I already did this with OnMouseWheel event and checking with PtInRect if Mouse.CursorPos if it is over a control but I have a feeling that there is a better way to do the same because this way I'd have to define a new event for each TreeView I add and also handle when to focus/unfocus the control so I hope there must be a better way to disable this.

很明显，我希望鼠标滚轮功能能够照常工作，但仅当鼠标悬停在VirtualTreeView上时.

So to be clear, I want mousewheel function to work as usual, but only when mouse is over VirtualTreeView.

推荐答案

将TApplicationEvents控件拖放到表单中

Drop down a TApplicationEvents control to the form

在TApplicationEvents onMessage

in TApplicationEvents onMessage

 procedure TForm5.ApplicationEvents1Message(var Msg: tagMSG; var Handled: Boolean);
 var
  pnt: TPoint;
  ctrl: TWinControl;
 begin
  if Msg.message = WM_MOUSEWHEEL then
  begin
    if not GetCursorPos(pnt) then Exit;
    ctrl := FindVCLWindow(pnt);
    if Assigned(ctrl) then
      Msg.hwnd := ctrl.Handle;
  end;
 end;

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