delphi – 如何在Chromium Embedded中禁用视图源选项？

1.告诉用户禁止查看源选项并拒绝操作

您可以决定OnMenuAction事件处理程序中允许或拒绝的操作,如果为Result参数指定True,则操作将被拒绝.以下代码检查您是否已执行视图源操作,如果是,请拒绝操作并显示信息消息：

type
  TCefMenuId = TCefHandlerMenuId;

procedure TForm1.Chromium1MenuAction(Sender: TObject;
  const browser: ICefBrowser; menuId: TCefMenuId; out Result: Boolean);
begin
  if menuId = MENU_ID_VIEWSOURCE then
  begin
    Result := True;
    ShowMessage('View page source is not allowed!');
  end;
end;

2.通过更改菜单项的标题及其操作,将菜单项伪造为自定义项

您可以通过更改菜单项的标题并执行一些自定义操作来利用菜单项.以下示例代码显示如何将视图源菜单项更改为about框菜单项：

type
  TCefMenuId = TCefHandlerMenuId;

procedure TForm1.Chromium1GetMenuLabel(Sender: TObject;
  const browser: ICefBrowser; menuId: TCefMenuId; var caption: ustring;
  out Result: Boolean);
begin
  if menuId = MENU_ID_VIEWSOURCE then
    caption := 'About my application...';
end;

procedure TForm1.Chromium1MenuAction(Sender: TObject;
  const browser: ICefBrowser; menuId: TCefMenuId; out Result: Boolean);
begin
  if menuId = MENU_ID_VIEWSOURCE then
  begin
    Result := True;
    ShowMessage('About box...!');
  end;
end;

3.创建自己的自定义页面(框架)弹出菜单

您可以创建自己的弹出菜单,但是您需要考虑此菜单是非常硬编码的,因此如果您需要在每个新版本的Delphi Chromium包装中使用它,则需要对其进行维护.以下是如何在没有查看源菜单项的情况下创建页面菜单的代码：

unit Unit1;

interface

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

type
  PCefMenuInfo = PCefHandlerMenuInfo;

type
  TForm1 = class(TForm)
    Chromium1: TChromium;
    procedure FormCreate(Sender: TObject);
    procedure Chromium1BeforeMenu(Sender: TObject; const browser: ICefBrowser;
      const menuInfo: PCefMenuInfo; out Result: Boolean);
  private
    PageMenu: TPopupMenu;
    procedure OnNavigateBackMenuItemClick(Sender: TObject);
    procedure OnNavigateForwardMenuItemClick(Sender: TObject);
    procedure OnPrintMenuItemClick(Sender: TObject);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.OnNavigateBackMenuItemClick(Sender: TObject);
begin
  Chromium1.Browser.GoBack;
end;

procedure TForm1.OnNavigateForwardMenuItemClick(Sender: TObject);
begin
  Chromium1.Browser.GoForward;
end;

procedure TForm1.OnPrintMenuItemClick(Sender: TObject);
begin
  Chromium1.Browser.GetFocusedFrame.Print;
end;

procedure TForm1.Chromium1BeforeMenu(Sender: TObject;
  const browser: ICefBrowser; const menuInfo: PCefMenuInfo;
  out Result: Boolean);
begin
  if menuInfo.typeFlags = MENUTYPE_PAGE then
  begin
    Result := True;
    PageMenu.Items[0].Enabled := browser.CanGoBack;
    PageMenu.Items[1].Enabled := browser.CanGoForward;
    PageMenu.Popup(menuInfo^.x,menuInfo^.y);
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  MenuItem: TMenuItem;
begin
  PageMenu := TPopupMenu.Create(Self);
  MenuItem := TMenuItem.Create(PageMenu);
  MenuItem.Caption := 'Back';
  MenuItem.OnClick := OnNavigateBackMenuItemClick;
  PageMenu.Items.Add(MenuItem);
  MenuItem := TMenuItem.Create(PageMenu);
  MenuItem.Caption := 'Forward';
  MenuItem.OnClick := OnNavigateForwardMenuItemClick;
  PageMenu.Items.Add(MenuItem);
  MenuItem := TMenuItem.Create(PageMenu);
  MenuItem.Caption := '-';
  PageMenu.Items.Add(MenuItem);
  MenuItem := TMenuItem.Create(PageMenu);
  MenuItem.Caption := 'Print';
  MenuItem.OnClick := OnPrintMenuItemClick;
  PageMenu.Items.Add(MenuItem);
  Chromium1.Load('www.stackoverflow.com');
end;

end.

脚注

所有代码示例中使用的类型定义都在那里,因为我注意到某些版本的Delphi Chromium具有错误的事件处理程序定义.