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在下面的 VCL Forms 应用程序中，Application.MainForm 被隐藏，而是显示另一个 TForm 后代。奇怪的是，只有这个TForm后代的名字以“TForm”开头，按Alt+Tab时才能看到。如果其名称不以“TForm”开头，则在 Alt+Tab 时看不到。以上是在 Windows 10 Ann Edition x64 上使用 Delphi XE-Berlin 测试的。

你能帮忙评论一下类名在这里很重要的原因吗？O_O

此外，TForm 后代的类名在其他地方是否重要？

程序

program Strange;

uses
  Forms,
  uHiddenMainForm in 'uHiddenMainForm.pas' {HiddenMainForm},
  uActualMainForm in 'uActualMainForm.pas' {FormActualMainForm};

{$R *.res}

begin
  Application.Initialize;
  Application.CreateForm(THiddenMainForm, HiddenMainForm);     // Note: WRONG ! Still, interesting strangeness.
  Application.ShowMainForm := False;
  Application.MainFormOnTaskbar := True;
  // Application.CreateForm(THiddenMainForm, HiddenMainForm);  // Note: CORRECT
  with TFormActualMainForm.Create(HiddenMainForm) do
  begin
    Show;
    Update;
  end;
  Application.Run;
end.

主窗体的单元（即 Application.MainForm）

    unit uHiddenMainForm;

    interface

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

    type
      THiddenMainForm = class(TForm)
      end;

    var
      HiddenMainForm: THiddenMainForm;

    implementation

    {$R *.dfm}

    end.

实际“主”表格的单位

    unit uActualMainForm;

    interface

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

    type
      TFormActualMainForm = class(TForm)
        procedure FormClose(Sender: TObject; var Action: TCloseAction);
      protected
        procedure CreateParams(var Params: TCreateParams) ; override;
      end;

    implementation

    {$R *.dfm}

    { TFormActualMainForm }

    procedure TFormActualMainForm.CreateParams(var Params: TCreateParams);
    begin
      inherited;
      Params.ExStyle := Params.ExStyle or WS_EX_APPWINDOW;
    end;

    procedure TFormActualMainForm.FormClose(Sender: TObject; var Action: TCloseAction);
    begin
      Application.Terminate;
    end;

    end.

问题If its name does not start with "TForm", it can not be seen when Alt+Tab.通过以下代码显示出来。唯一的区别是类名从 TFormActualMainForm 更改为 TXFormActualMainForm。

程序

program Strange;

uses
  Forms,
  uHiddenMainForm in 'uHiddenMainForm.pas' {HiddenMainForm},
  uActualMainForm in 'uActualMainForm.pas' {XFormActualMainForm};

{$R *.res}

begin
  Application.Initialize;
  Application.CreateForm(THiddenMainForm, HiddenMainForm);     
  Application.ShowMainForm := False;
  Application.MainFormOnTaskbar := True;
  with TXFormActualMainForm.Create(HiddenMainForm) do
  begin
    Visible := True;
  end;
  Application.Run;
end.

实际“主”表格的单位

    unit uActualMainForm;

    interface

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

    type
      TXFormActualMainForm = class(TForm)
        procedure FormClose(Sender: TObject; var Action: TCloseAction);
      protected
        procedure CreateParams(var Params: TCreateParams) ; override;
      end;

    implementation

    {$R *.dfm}

    { TXFormActualMainForm }

    procedure TXFormActualMainForm.CreateParams(var Params: TCreateParams);
    begin
      inherited;
      Params.ExStyle := Params.ExStyle or WS_EX_APPWINDOW;
    end;

    procedure TXFormActualMainForm.FormClose(Sender: TObject; var Action: TCloseAction);
    begin
      Application.Terminate;
    end;

    end.
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