德尔福 - 我如何找出哪个模态对话框的重点放在前面？ [英] Delphi - how do I find out which modal dialog has focus and bring it to the front?

问题描述

我有一个Delphi 2006应用程序，可以弹出一个模态对话框来响应错误条件。似乎让自己进入一个这样的状态，其中一个模态对话是开放的，位于主窗体的前面，但两个窗体都不响应消息。点击或者给出一个bonk。该应用程序运行正常，UI正在更新主窗体，但您不能做任何事情。我想可能是主要形式下的另一个模态对话框。无论是我的一个还是Windows中的一个，我都不知道。

其他要点：

• 该应用程序响应键盘快捷键确定。其中一个这样的短路程序优雅地关闭应用程序，这样做有效。我自此以来一直无法重现这种情况。


• 该应用有一个托盘图标。这会响应鼠标右键点击。如果我从这里最小化应用程序，主窗体最小化并保留模式对话框显示，仍然没有焦点。如果我恢复了主要的形式，事情就是这样，既没有窗口有焦点。 Alt-tab具有类似的结果。


• 平台是Windows 7


• 在任何表单创建之前，我调用DisableProcessWindowsGhosting



• 与

    ModalDialog.PopupParent：= MainForm; 
   ModalDialog.ShowModal; 
    




• 如果其他模式对话框打开，我推迟了这些错误对话框：

    if（Application.ModalLevel = 0）then 
   {open modal dialog} 
    

我的问题有两个部分：

是否以编程方式发现什么窗口有焦点？我可以为这种情况采取一些行动，或者最后的手段，我们可以提供一个快捷键，将其带到前面或采取一些回避行动（取决于对话框），如将ModalResult设置为mrCancel。

如何发生这种情况？通常当我在主窗体后面得到一个模态对话框（我可以通过获取模态对话框打开，最小化托盘图标的应用程序，然后再次恢复应用程序 - 应用程序主窗体在对话框前面恢复，对话框仍然保留焦点），我可以通过点击托盘图标将其重新放在前面，或者使用 Esc 键关闭它，但是在此不起作用

**更新* * b

Misha的修复工作与非delphi对话框（如TSaveDialog）相去甚远。在调用执行之前添加 Application.ModalPopupMode：= pmAuto; 也可以让他们工作。 >。

通过让它工作我的意思是保存对话框按照以下顺序在前面：

打开保存对话框

从托盘图标中最小化应用

从托盘图标还原应用

而不是 ModalPopupMode：= pmAuto 的主窗体后面。

所以我希望这些更改将有助于（至今未被再现）的问题。

解决方案

最后一个活动的弹出窗口（VCL或否）可以使用 GetLastActivePopup ：

  function GetTopWindow：HWND; 
 begin 
结果：= GetLastActivePopup（Application.Handle）; 
 if（Result = 0）或（Result = Application.Handle）或
不是IsWindowVisible（Result）then 
结果：= Screen.ActiveCustomForm.Handle; 
结束
  

这是从 TApplication.BringToFront 。

将此窗口放在前面可以通过 SetForegroundWindow ：

  SetForegroundWindow（GetTopWindow）; 
  

请注意， Application.BringToFront 可能会但是我一度体验到它没有正常运作，这种情况我从来没有能够再现。

I have a Delphi 2006 app which can pop up a modal dialog in response to an error condition. It seems to get itself into a state where one of these modal dialogs is open, positioned in front of the main form, but neither form is responding to messages. Clicking on either gives a "bonk". The app is running fine, the UI is updating the main form, but you can't do anything. I guess there is most likely another modal dialog under the main form. Whether it is one of mine or one from Windows I have no idea.

Other points:

• the app responds to keyboard shortcuts OK. One of these shortuts shuts down the app gracefully and this worked. I have been unable to reproduce the situation since.
• the app has a tray icon. This responds to right mouse clicks. If I minimize the app from here the main form minimizes and leaves the modal dialog displayed, still without focus. If I restore the main form, things are as they were, with neither window having focus. Alt-tab has similar results.
• platform is Windows 7
• I call DisableProcessWindowsGhosting before any forms are created

• I open the modal dialogs with

  ModalDialog.PopupParent := MainForm ;
  ModalDialog.ShowModal ;
  

• I postpone these error dialogs if other modal dialogs are open:

  if (Application.ModalLevel = 0) then
      {open modal dialog}
  

My question has two parts:

Is there a way of programmatically finding out what window has focus? I could then take some action for this scenario or a last resort I could them provide a shortcut key to bring it to the front or take some evasive action (depending on the dialog) like set the ModalResult to mrCancel.

How can this situation arise? Normally when I get a modal dialog behind the main form (I can do that by getting the modal dialog to open, minimizing the app from the tray icon, then restoring the app again - the app main form restores in front of the dialog, with the dialog still retaining focus), I can bring it to the front again by clicking on the tray icon, or close it with the Esc key but it didn't work in this case.

**UPDATE**

Misha's fix worked apart from non-delphi dialogs like TSaveDialog. I was able to get them to work as well by adding Application.ModalPopupMode := pmAuto ; just before the call to Execute.

By "got it to work" I mean that the save dialog was in front after the following sequence:

• open save dialog
• minimize app from tray icon
• restore app from tray icon

whereas it was behind the main form without the ModalPopupMode := pmAuto.

So I'm hoping these changes will help the (as yet unreproduced) problem.

解决方案

The last active popup window (VCL or not) can be queried with GetLastActivePopup:

function GetTopWindow: HWND;
begin
  Result := GetLastActivePopup(Application.Handle);
  if (Result = 0) or (Result = Application.Handle) or
      not IsWindowVisible(Result) then
    Result := Screen.ActiveCustomForm.Handle;
end;

This is somewhat copied from TApplication.BringToFront.

Bringing this window to the front can be done by SetForegroundWindow:

SetForegroundWindow(GetTopWindow);

Note that Application.BringToFront might do the trick altogether, but I once experienced it did not function properly, a situation I have not been able to reproduce since though.

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