/// <summary>
        /// 屏蔽右键
        /// </summary>
        internal class MenuHandler : IContextMenuHandler
        {
            public bool OnBeforeContextMenu(IWebBrowser browser, IBrowser ibrower, IFrame iframe, IContextMenuParams icontextmenuparams, IMenuModel imenumodel)
            {
                return false;
            }
            void CefSharp.IContextMenuHandler.OnBeforeContextMenu(CefSharp.IWebBrowser browserControl, CefSharp.IBrowser browser, CefSharp.IFrame frame, CefSharp.IContextMenuParams parameters, CefSharp.IMenuModel model)
            {
                model.Clear();
            }

            bool CefSharp.IContextMenuHandler.OnContextMenuCommand(CefSharp.IWebBrowser browserControl, CefSharp.IBrowser browser, CefSharp.IFrame frame, CefSharp.IContextMenuParams parameters, CefSharp.CefMenuCommand commandId, CefSharp.CefEventFlags eventFlags)
            {
                //throw new NotImplementedException();
                return false;
            }

            void CefSharp.IContextMenuHandler.OnContextMenuDismissed(CefSharp.IWebBrowser browserControl, CefSharp.IBrowser browser, CefSharp.IFrame frame)
            {
                //throw new NotImplementedException();
            }

            bool CefSharp.IContextMenuHandler.RunContextMenu(CefSharp.IWebBrowser browserControl, CefSharp.IBrowser browser, CefSharp.IFrame frame, CefSharp.IContextMenuParams parameters, CefSharp.IMenuModel model, CefSharp.IRunContextMenuCallback callback)
            {
                return false;
            }
        }

使用：在form中初始化即可

_browser.MenuHandler = new MenuHandler();