Pascal文件

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    ActionList1: TActionList;
    Action1: TAction;
    CheckBox1: TCheckBox;
    procedure Action1Update(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Action1Update(Sender: TObject);
begin
  (Sender as TAction).Visible := CheckBox1.Checked;
end;

end.

表格文件

object Form1: TForm1
  object Button1: TButton
    Left = 8
    Top = 31
    Action = Action1
  end
  object CheckBox1: TCheckBox
    Left = 8
    Top = 8
    Caption = 'CheckBox1'
    Checked = True
    State = cbChecked
  end
  object ActionList1: TActionList
    Left = 128
    Top = 8
    object Action1: TAction
      Caption = 'Action1'
      OnUpdate = Action1Update
    end
  end
end

首次运行表单时,按钮可见,并选中复选框.然后我取消选中复选框,按钮消失.当我重新选中复选框时,该按钮无法重新出现.

我认为这个的原因可以在TCustomForm.UpdateActions中的以下本地函数中找到：

procedure TraverseClients(Container: TWinControl);
var
  I: Integer;
  Control: TControl;
begin
  if Container.Showing and not (csDesigning in Container.ComponentState) then
    for I := 0 to Container.ControlCount - 1 do
    begin
      Control := Container.Controls[I];
      if (csActionClient in Control.ControlStyle) and Control.Visible then
          Control.InitiateAction;
      if (Control is TWinControl) and (TWinControl(Control).ControlCount > 0) then
        TraverseClients(TWinControl(Control));
    end;
end;

Control.Visible的检查似乎阻止我的行动再次有机会自我更新.

我是否正确诊断了该问题？这是设计还是我应该提交质量控制报告？有没有人知道一个解决方法？