为什么打开画布时我的固定菜单将固定div推开了？

Question

我在网站上使用Pushy off-canvas菜单 ，它的工作原理很棒，但是却困扰着我固定的div标头 。 当我向下滚动页面时，标题完美地贴在顶部，但是一旦打开画布菜单，标题消失了吗？ 当我关闭画布菜单时，它突然返回。 看起来很奇怪。

您可以在此处查看我的问题的（ 代码笔 ） 实时演示。 或直接运行下面的代码段。

我希望在打开画布菜单时保持可见状态。 帮助将不胜感激。
提前致谢。

 /*! Pushy - v1.0.0 - 2016-3-1 * Pushy is a responsive off-canvas navigation menu using CSS transforms & transitions. * https://github.com/christophery/pushy/ * by Christopher Yee */ (function($) { var pushy = $('.pushy'), //menu css class body = $('body'), container = $('#container'), //container css class push = $('.push'), //css class to add pushy capability pushyLeft = 'pushy-left', //css class for left menu position pushyOpenLeft = 'pushy-open-left', //css class when menu is open (left position) pushyOpenRight = 'pushy-open-right', //css class when menu is open (right position) siteOverlay = $('.site-overlay'), //site overlay menuBtn = $('.menu-btn, .pushy-link'), //css classes to toggle the menu menuSpeed = 200, //jQuery fallback menu speed menuWidth = pushy.width() + 'px', //jQuery fallback menu width submenuClass = '.pushy-submenu', submenuOpenClass = 'pushy-submenu-open', submenuClosedClass = 'pushy-submenu-closed', submenu = $(submenuClass); function togglePushy() { //add class to body based on menu position if (pushy.hasClass(pushyLeft)) { body.toggleClass(pushyOpenLeft); } else { body.toggleClass(pushyOpenRight); } } function openPushyFallback() { //animate menu position based on CSS class if (pushy.hasClass(pushyLeft)) { body.addClass(pushyOpenLeft); pushy.animate({ left: "0px" }, menuSpeed); container.animate({ left: menuWidth }, menuSpeed); //css class to add pushy capability push.animate({ left: menuWidth }, menuSpeed); } else { body.addClass(pushyOpenRight); pushy.animate({ right: '0px' }, menuSpeed); container.animate({ right: menuWidth }, menuSpeed); push.animate({ right: menuWidth }, menuSpeed); } } function closePushyFallback() { //animate menu position based on CSS class if (pushy.hasClass(pushyLeft)) { body.removeClass(pushyOpenLeft); pushy.animate({ left: "-" + menuWidth }, menuSpeed); container.animate({ left: "0px" }, menuSpeed); //css class to add pushy capability push.animate({ left: "0px" }, menuSpeed); } else { body.removeClass(pushyOpenRight); pushy.animate({ right: "-" + menuWidth }, menuSpeed); container.animate({ right: "0px" }, menuSpeed); push.animate({ right: "0px" }, menuSpeed); } } function toggleSubmenu() { //hide submenu by default $(submenuClass).addClass(submenuClosedClass); $(submenuClass).on('click', function() { var selected = $(this); if (selected.hasClass(submenuClosedClass)) { //hide opened submenus $(submenuClass).addClass(submenuClosedClass).removeClass(submenuOpenClass); //show submenu selected.removeClass(submenuClosedClass).addClass(submenuOpenClass); } else { //hide submenu selected.addClass(submenuClosedClass).removeClass(submenuOpenClass); } }); } function toggleSubmenuFallback() { //hide submenu by default $(submenuClass).addClass(submenuClosedClass); submenu.children('a').on('click', function(event) { event.preventDefault(); $(this).toggleClass(submenuOpenClass) .next('.pushy-submenu ul').slideToggle(200) .end().parent(submenuClass) .siblings(submenuClass).children('a') .removeClass(submenuOpenClass) .next('.pushy-submenu ul').slideUp(200); }); } //checks if 3d transforms are supported removing the modernizr dependency var cssTransforms3d = (function csstransforms3d() { var el = document.createElement('p'), supported = false, transforms = { 'webkitTransform': '-webkit-transform', 'OTransform': '-o-transform', 'msTransform': '-ms-transform', 'MozTransform': '-moz-transform', 'transform': 'transform' }; // Add it to the body to get the computed style document.body.insertBefore(el, null); for (var t in transforms) { if (el.style[t] !== undefined) { el.style[t] = 'translate3d(1px,1px,1px)'; supported = window.getComputedStyle(el).getPropertyValue(transforms[t]); } } document.body.removeChild(el); return (supported !== undefined && supported.length > 0 && supported !== "none"); })(); if (cssTransforms3d) { //make menu visible pushy.css({ 'visibility': 'visible' }); //toggle submenu toggleSubmenu(); //toggle menu menuBtn.on('click', function() { togglePushy(); }); //close menu when clicking site overlay siteOverlay.on('click', function() { togglePushy(); }); } else { //add css class to body body.addClass('no-csstransforms3d'); //hide menu by default if (pushy.hasClass(pushyLeft)) { pushy.css({ left: "-" + menuWidth }); } else { pushy.css({ right: "-" + menuWidth }); } //make menu visible pushy.css({ 'visibility': 'visible' }); //fixes IE scrollbar issue container.css({ "overflow-x": "hidden" }); //keep track of menu state (open/close) var opened = false; //toggle submenu toggleSubmenuFallback(); //toggle menu menuBtn.on('click', function() { if (opened) { closePushyFallback(); opened = false; } else { openPushyFallback(); opened = true; } }); //close menu when clicking site overlay siteOverlay.on('click', function() { if (opened) { closePushyFallback(); opened = false; } else { openPushyFallback(); opened = true; } }); } }(jQuery)); 

 body { margin: 0px; } div.header { padding: 10px; box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19); position: fixed; top: 0; width: 100%; height: 40px; background: white; z-index: 100; } div.content { padding-top: 70px; padding-left: 300px; padding-right: 300px; } div.menu-btn { float: left; font-size: 20px; } /*! Pushy - v1.0.0 - 2016-3-1 * Pushy is a responsive off-canvas navigation menu using CSS transforms & transitions. * https://github.com/christophery/pushy/ * by Christopher Yee */ /* Menu Appearance */ .pushy { position: fixed; width: 200px; height: 100%; top: 0; z-index: 9999; background: #191918; overflow: auto; visibility: hidden; -webkit-overflow-scrolling: touch; /* enables momentum scrolling in iOS overflow elements */ } .pushy a { display: block; color: #b3b3b1; padding: 15px 30px; text-decoration: none; outline: 0; } .pushy a:hover { color: #FFF; } .pushy ul:first-child { margin-top: 10px; } .pushy.pushy-left { left: 0; } .pushy.pushy-right { right: 0; } /* Menu Movement */ .pushy-left { -webkit-transform: translate3d(-200px, 0, 0); -ms-transform: translate3d(-200px, 0, 0); transform: translate3d(-200px, 0, 0); } .pushy-open-left #container, .pushy-open-left .push { -webkit-transform: translate3d(200px, 0, 0); -ms-transform: translate3d(200px, 0, 0); transform: translate3d(200px, 0, 0); } .pushy-right { -webkit-transform: translate3d(200px, 0, 0); -ms-transform: translate3d(200px, 0, 0); transform: translate3d(200px, 0, 0); } .pushy-open-right #container, .pushy-open-right .push { -webkit-transform: translate3d(-200px, 0, 0); -ms-transform: translate3d(-200px, 0, 0); transform: translate3d(-200px, 0, 0); } .pushy-open-left .pushy, .pushy-open-right .pushy { -webkit-transform: translate3d(0, 0, 0); -ms-transform: translate3d(0, 0, 0); transform: translate3d(0, 0, 0); } /* Menu Transitions */ #container, .pushy, .push { transition: transform 0.2s cubic-bezier(0.16, 0.68, 0.43, 0.99); } /* Site Overlay */ .site-overlay { display: none; } .pushy-open-left .site-overlay, .pushy-open-right .site-overlay { display: block; position: fixed; top: 0; right: 0; bottom: 0; left: 0; z-index: 9998; background-color: rgba(0, 0, 0, 0.5); -webkit-animation: fade 500ms; animation: fade 500ms; } @keyframes fade { 0% { opacity: 0; } 100% { opacity: 1; } } @-webkit-keyframes fade { 0% { opacity: 0; } 100% { opacity: 1; } } /* Submenu Appearance */ .pushy-submenu { /* Submenu Icon */ } .pushy-submenu ul { padding-left: 15px; transition: max-height 0.2s ease-in-out; } .pushy-submenu ul .pushy-link { transition: opacity 0.2s ease-in-out; } .pushy-submenu > a { position: relative; } .pushy-submenu > a::after { content: ''; display: block; height: 11px; width: 8px; position: absolute; top: 50%; right: 15px; background: url("../img/arrow.svg") no-repeat; -webkit-transform: translateY(-50%); -ms-transform: translateY(-50%); transform: translateY(-50%); transition: transform 0.2s; } /* Submenu Movement */ .pushy-submenu-closed ul { max-height: 0; overflow: hidden; } .pushy-submenu-closed .pushy-link { opacity: 0; } .pushy-submenu-open { /* Submenu Icon */ } .pushy-submenu-open ul { max-height: 1000px; } .pushy-submenu-open .pushy-link { opacity: 1; } .pushy-submenu-open a::after { -webkit-transform: translateY(-50%) rotate(90deg); -ms-transform: translateY(-50%) rotate(90deg); transform: translateY(-50%) rotate(90deg); } .no-csstransforms3d .pushy-submenu-closed ul { max-height: none; display: none; } /*# sourceMappingURL=pushy.css.map */ 

 <!-- jQuery --> <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script> <body> <!-- Pushy Menu --> <nav class="pushy pushy-left"> </nav> <!-- Site Overlay --> <div class="site-overlay"></div> <!-- Your Content --> <div id="container"> <div class="header"> <div class="menu-btn">&#9776; Sroll down a bit and Click me, I vanish (get stuck at top)</div> </div> <div align="center" class="content"> <h1> Lorem Ipsum </h1> <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut, imperdiet a, venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt. Cras dapibus. Vivamus elementum semper nisi. Aenean vulputate eleifend tellus. Aenean leo ligula, porttitor eu, consequat vitae, eleifend ac, enim. Aliquam lorem ante, dapibus in, viverra quis, feugiat a, tellus. Phasellus viverra nulla ut metus varius laoreet. Quisque rutrum. Aenean imperdiet. Etiam ultricies nisi vel augue. Curabitur ullamcorper ultricies nisi. Nam eget dui. Etiam rhoncus. Maecenas tempus, tellus eget condimentum rhoncus, sem quam semper libero, sit amet adipiscing sem neque sed ipsum. Nam quam nunc, blandit vel, luctus pulvinar, hendrerit id, lorem. Maecenas nec odio et ante tincidunt tempus. Donec vitae sapien ut libero venenatis faucibus. Nullam quis ante. Etiam sit amet orci eget eros faucibus tincidunt. Duis leo. Sed fringilla mauris sit amet nibh. Donec sodales sagittis magna. Sed consequat, leo eget bibendum sodales, augue velit cursus nunc,</p> <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut, imperdiet a, venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt. Cras dapibus. Vivamus elementum semper nisi. Aenean vulputate eleifend tellus. Aenean leo ligula, porttitor eu, consequat vitae, eleifend ac, enim. Aliquam lorem ante, dapibus in, viverra quis, feugiat a, tellus. Phasellus viverra nulla ut metus varius laoreet. Quisque rutrum. Aenean imperdiet. Etiam ultricies nisi vel augue. Curabitur ullamcorper ultricies nisi. Nam eget dui. Etiam rhoncus. Maecenas tempus, tellus eget condimentum rhoncus, sem quam semper libero, sit amet adipiscing sem neque sed ipsum. Nam quam nunc, blandit vel, luctus pulvinar, hendrerit id, lorem. Maecenas nec odio et ante tincidunt tempus. Donec vitae sapien ut libero venenatis faucibus. Nullam quis ante. Etiam sit amet orci eget eros faucibus tincidunt. Duis leo. Sed fringilla mauris sit amet nibh. Donec sodales sagittis magna. Sed consequat, leo eget bibendum sodales, augue velit cursus nunc,</p> <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut, imperdiet a, venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt. Cras dapibus. Vivamus elementum semper nisi. Aenean vulputate eleifend tellus. Aenean leo ligula, porttitor eu, consequat vitae, eleifend ac, enim. Aliquam lorem ante, dapibus in, viverra quis, feugiat a, tellus. Phasellus viverra nulla ut metus varius laoreet. Quisque rutrum. Aenean imperdiet. Etiam ultricies nisi vel augue. Curabitur ullamcorper ultricies nisi. Nam eget dui. Etiam rhoncus. Maecenas tempus, tellus eget condimentum rhoncus, sem quam semper libero, sit amet adipiscing sem neque sed ipsum. Nam quam nunc, blandit vel, luctus pulvinar, hendrerit id, lorem. Maecenas nec odio et ante tincidunt tempus. Donec vitae sapien ut libero venenatis faucibus. Nullam quis ante. Etiam sit amet orci eget eros faucibus tincidunt. Duis leo. Sed fringilla mauris sit amet nibh. Donec sodales sagittis magna. Sed consequat, leo eget bibendum sodales, augue velit cursus nunc,</p> <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut, imperdiet a, venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt. Cras dapibus. Vivamus elementum semper nisi. Aenean vulputate eleifend tellus. Aenean leo ligula, porttitor eu, consequat vitae, eleifend ac, enim. Aliquam lorem ante, dapibus in, viverra quis, feugiat a, tellus. Phasellus viverra nulla ut metus varius laoreet. Quisque rutrum. Aenean imperdiet. Etiam ultricies nisi vel augue. Curabitur ullamcorper ultricies nisi. Nam eget dui. Etiam rhoncus. Maecenas tempus, tellus eget condimentum rhoncus, sem quam semper libero, sit amet adipiscing sem neque sed ipsum. Nam quam nunc, blandit vel, luctus pulvinar, hendrerit id, lorem. Maecenas nec odio et ante tincidunt tempus. Donec vitae sapien ut libero venenatis faucibus. Nullam quis ante. Etiam sit amet orci eget eros faucibus tincidunt. Duis leo. Sed fringilla mauris sit amet nibh. Donec sodales sagittis magna. Sed consequat, leo eget bibendum sodales, augue velit cursus nunc,</p> <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut, imperdiet a, venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt. Cras dapibus. Vivamus elementum semper nisi. Aenean vulputate eleifend tellus. Aenean leo ligula, porttitor eu, consequat vitae, eleifend ac, enim. Aliquam lorem ante, dapibus in, viverra quis, feugiat a, tellus. Phasellus viverra nulla ut metus varius laoreet. Quisque rutrum. Aenean imperdiet. Etiam ultricies nisi vel augue. Curabitur ullamcorper ultricies nisi. Nam eget dui. Etiam rhoncus. Maecenas tempus, tellus eget condimentum rhoncus, sem quam semper libero, sit amet adipiscing sem neque sed ipsum. Nam quam nunc, blandit vel, luctus pulvinar, hendrerit id, lorem. Maecenas nec odio et ante tincidunt tempus. Donec vitae sapien ut libero venenatis faucibus. Nullam quis ante. Etiam sit amet orci eget eros faucibus tincidunt. Duis leo. Sed fringilla mauris sit amet nibh. Donec sodales sagittis magna. Sed consequat, leo eget bibendum sodales, augue velit cursus nunc,</p> </div> </div> </body> </html> 

Answer 1

在pushy中有一个封闭的问题 ：

诀窍是在容器div之外具有任何固定位置（如固定标头）的元素。 有关示例，请参见demo.html。

在您的情况下，将.header #container可以。

如果您对造成这种情况的原因感兴趣，请参见此答案 。