如何顯示其所有者窗體頂部的模式窗體（其所有者設置爲fsStayOnTop與否），就像TOpenDialog確實

Question

綜述：

請參閱從克雷格和Sertac下面的有益的意見。

============================================== ========

如以下最小化代碼所示，TForm10設置爲fsStayOnTop。 TForm10.btnTryDlgClick致電dlgOpen1.Execute，並顯示對話框如預期。但是，當我在TForm10.btnTryFormClick內調用TForm11.Create(Self).ShowModal時，窗體將隱藏在TForm10的後面。我想知道如何理解這種行爲，爲什麼標準的TOpenDialog可以按預期顯示？任何評論感謝！

PS：一種解決方法是重寫TForm11的CreateParams過程，並將Params.wndParent設置爲0.但是在我看來，使用此解決方法將打破窗口層次結構。

procedure TForm11.CreateParams(var Params: TCreateParams); // override; 
    begin 
    inherited; 
    params.wndParent := 0; 
    end; 

PS：另外一個辦法是由雷米在下文提到的相關網頁SO：setting the modal Form's PopupParent property to be the StayOnTop Form。但在接下來的評論中，Sertac提到這個解決方法也會打破窗口層次結構。

PS：可能相關的SO網頁：
Modal forms hidden by fsStayOnTop forms
How Can I Keep the FindDialog from Staying on Top (Delphi)?
How to make sure a dialog is always front of the main window
Form is hidden behind other forms when ShowModal is called
Make 2 forms able to overlap each other?
Multiple form Delphi applications and dialogs
Newly created modal window loses focus and become inacessible in Windows Vista
Delphi - How to prevent Forms/MsgBoxes to move under prior form?
How to allow Delphi secondary forms behind the main form
Fake modal dialog using Show?
Delphi MainFormOnTaskBar Modal windows bug

來源爲Unit10：

unit Unit10; 

    interface 

    uses 
     Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, 
     Dialogs, StdCtrls; 

    type 
     TForm10 = class(TForm) 
     btnTryDlg: TButton; 
     dlgOpen1: TOpenDialog; 
     btnTryForm: TButton; 
     procedure FormCreate(Sender: TObject); 
     procedure btnTryDlgClick(Sender: TObject); 
     procedure btnTryFormClick(Sender: TObject); 
     end; 

    var 
     Form10: TForm10; 

    implementation 

    {$R *.dfm} 

    uses 
     Unit11; 

    procedure TForm10.FormCreate(Sender: TObject); 
    begin 
     FormStyle := fsStayOnTop; 
    end; 

    procedure TForm10.btnTryDlgClick(Sender: TObject); 
    begin 
     dlgOpen1.Execute; 
    // dlgOpen1.Execute(Self.Handle); 
    end; 

    procedure TForm10.btnTryFormClick(Sender: TObject); 
    begin 
     TForm11.Create(Self).ShowModal; 
    end; 

    end. 

DFM爲Unit10：

object Form10: TForm10 
     Left = 0 
     Top = 0 
     Caption = 'Form10' 
     ClientHeight = 255 
     ClientWidth = 414 
     Color = clBtnFace 
     Font.Charset = DEFAULT_CHARSET 
     Font.Color = clWindowText 
     Font.Height = -11 
     Font.Name = 'Tahoma' 
     Font.Style = [] 
     OldCreateOrder = False 
     OnCreate = FormCreate 
     PixelsPerInch = 96 
     TextHeight = 13 
     object btnTryDlg: TButton 
     Left = 32 
     Top = 24 
     Width = 153 
     Height = 201 
     Caption = 'Try dialog' 
     TabOrder = 0 
     OnClick = btnTryDlgClick 
     end 
     object btnTryForm: TButton 
     Left = 224 
     Top = 24 
     Width = 153 
     Height = 201 
     Caption = 'btnTryForm' 
     TabOrder = 1 
     OnClick = btnTryFormClick 
     end 
     object dlgOpen1: TOpenDialog 
     Left = 96 
     Top = 168 
     end 
    end 

來源爲Unit11：

unit Unit11; 

    interface 

    uses 
     Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, 
     Dialogs; 

    type 
     TForm11 = class(TForm) 
     end; 


    implementation 

    {$R *.dfm} 

    end. 

DFM爲Unit11：

object Form11: TForm11 
     Left = 0 
     Top = 0 
     Caption = 'Form11' 
     ClientHeight = 183 
     ClientWidth = 203 
     Color = clBtnFace 
     Font.Charset = DEFAULT_CHARSET 
     Font.Color = clWindowText 
     Font.Height = -11 
     Font.Name = 'Tahoma' 
     Font.Style = [] 
     OldCreateOrder = False 
     PixelsPerInch = 96 
     TextHeight = 13 
    end 

Answer 1

設置模態窗體的PopupParent屬性，就像Remy建議的一樣。這將使對話框成爲StayOnTop表單，這是對話框的Execute方法已經在做的事情。我不確定Sertac的評論是從哪裏來的，但是使用PopupParent正確設置窗口heirarchy，所以對話框總是在StayOnTop窗體上方。