windows – 在最小化/恢复动画打开时,如何在删除任务栏按钮之前

删除表单的任务栏按钮时,下面的代码没有记录,特别是使用SetWindowLongPtr的GWLP_HWNDPARENT索引.在任何情况下,删除任务栏按钮并不笨拙,就像将窗口转换为工具窗口一样,动画也很流畅.

代码回退到一个计时器,该计时器隐藏表单,以防删除任务栏按钮失败.

type
  TForm1 = class(TForm)
    TrayIcon1: TTrayIcon;
    Timer1: TTimer;
    procedure TrayIcon1DblClick(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  protected
    procedure WMSize(var Message: TWMSize); message WM_SIZE;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function ShowTaskbarButton(Wnd: HWND; Show: Boolean = True;
    OwnerWnd: HWND = 0): Boolean;
var
  ExStyle,HWndParent: LONG_PTR;
  IsToolWindow: Boolean;
begin
  HwndParent := GetWindowLongPtr(Wnd,GWLP_HWNDPARENT);
  ExStyle := GetWindowLongPtr(Wnd,GWL_EXSTYLE);
  Result := Show = (HWndParent = 0) and (ExStyle and WS_EX_APPWINDOW <> 0);

  if not Result then begin
    IsToolWindow := ExStyle and WS_EX_TOOLWINDOW <> 0;
    if IsToolWindow then begin
      ShowWindow(Wnd,SW_HIDE);
      ShowWindowAsync(Wnd,SW_SHOW);
    end;
    SetLastError(0);
    if Show then
      SetWindowLongPtr(Wnd,GWL_EXSTYLE,ExStyle or WS_EX_APPWINDOW)
    else
      SetWindowLongPtr(Wnd,ExStyle and not WS_EX_APPWINDOW);
    if not IsToolWindow and (GetLastError = 0) then
      SetWindowLongPtr(Wnd,GWLP_HWNDPARENT,OwnerWnd);

    Result := GetLastError = 0;
  end;
end;

procedure TForm1.WMSize(var Message: TWMSize);
begin
  inherited;
  case Message.SizeType of
    SIZE_MINIMIZED:
      if not TrayIcon1.Visible then begin
        if not ShowTaskbarButton(Handle,False,Application.Handle) then
          Timer1.Enabled := True;   // fall back
        TrayIcon1.Visible := True
      end;
    SIZE_RESTORED,SIZE_MAXIMIZED:
      if TrayIcon1.Visible then begin
        ShowTaskbarButton(Handle);
        Application.BringToFront;
        TrayIcon1.Visible := False;
      end;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Timer1.Interval := 250;
  Timer1.Enabled := False;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  Hide;
  Timer1.Enabled := False;
end;

procedure TForm1.TrayIcon1DblClick(Sender: TObject);
begin
  ShowTaskbarButton(Handle);
  if not Showing then   // used timer to hide
    Show;
  WindowState := wsNormal;
end;