BttrLazyLoading 是一款响应式图像延迟加载的 jQuery 插件，允许用户的 web 应用延迟图片的加载直到图像滚动。BttrLazyLoading 提供四种不同的屏幕大小版本： 手机 (<768px), 平板 (≥768px), 桌面 (≥992px) 和大型的桌面 (≥1200px)。在线演示

API

Options

• delay: Adds delay to the image loading time.
• threshold: By default images are loaded when they appear on the screen. If you want images to load earlier use threshold parameter. Setting threshold to 200 causes image to load 200 pixels before it appears on viewport.
• animation: Adds an animation when the image loads. Animations available: ['flipInX', 'flipInY', 'fadeIn', 'fadeInUp', 'fadeInDown', 'fadeInLeft', 'fadeInRight', 'fadeInUpBig', 'fadeInDownBig', 'fadeInLeftBig', 'fadeInRightBig', 'slideInDown', 'slideInLeft', 'slideInRight', 'bounceIn', 'bounceInDown', 'bounceInUp', 'bounceInLeft', 'bounceInRight', 'rotateIn', 'rotateInDownLeft', 'rotateInDownRight', 'rotateInUpLeft', 'rotateInUpRight', 'lightSpeedIn', 'rollIn']
• event: Defines the event that will be use to trigger the image loading/updating.
• placeholder: Base 64 image that is used when the image loads.
• container: You can also use this plugin for images inside scrolling container, such as div with scrollbar. By default the container is the window.
• retina: Enable a better quality on Retina screens. BttrLazyLoading uses a naming convention @2x to display retina's images. BttrLazyLoading will therefore seek for "yourImage@2x.gif" on retina' screens instead of "yourImage.gif"
• triggermanually: Whether or not to trigger the first image load manually.
• updatemanually: Whether or not to trigger the image update (needed when the window resizes for example) manually.
• backgroundcolor: The background color of your images that are not loaded yet.
• xs: Image Object for Mobile
• sm: Image Object for Tablet
• md: Image Object for Desktop
• lg: Image Object for Large Desktop

Events

• bttrlazyloading.beforeLoad: This event is triggered just before the "bttrlazyloading.load" event.
• bttrlazyloading.load: This event is triggered when the image loading is triggered.
• bttrlazyloading.afterLoad: This event is triggered just after the "bttrlazyloading.load" event.
• bttrlazyloading.error: This event is triggered when none of the images (xs, sm, md and lg) exist. The classic "error" event could therefore be triggered up to 8 times (4 times for a normal screen and 8 times for a retina screen) while "bttrlazyloading.error" will be triggered only once.

Examples

Set options on instanciation

Via data attributes

<img id="yourImageId" class="bttrlazyloading"      data-bttrlazyloading-xs-src="img/768x200.gif"      data-bttrlazyloading-sm-src="img/345x250.gif"      data-bttrlazyloading-md-src="img/455x350.gif"      data-bttrlazyloading-lg-src="img/360x300.gif"      data-bttrlazyloading-transition="rotatedIn"      data-bttrlazyloading-retina="true"      data-bttrlazyloading-delay="2000"      data-bttrlazyloading-event="mouseover"      data-bttrlazyloading-container="document.body"      data-bttrlazyloading-threshold="500"  />

For a perfect experience 'width' and 'height' are necessary (The plugin cannot know the dimensions of your images before they load.).

<img id="test" class="bttrlazyloading"      data-bttrlazyloading-xs-src="img/768x200.gif"      data-bttrlazyloading-xs-width="768"      data-bttrlazyloading-xs-height="200"      data-bttrlazyloading-sm-src="img/345x250.gif"      data-bttrlazyloading-sm-width="345"      data-bttrlazyloading-sm-height="250"      data-bttrlazyloading-md-src="img/455x350.gif"      data-bttrlazyloading-md-width="455"      data-bttrlazyloading-md-height="350"      data-bttrlazyloading-lg-src="img/360x300.gif"      data-bttrlazyloading-lg-width="360"      data-bttrlazyloading-lg-height="300"  />

or

<img id="yourImageId" class="bttrlazyloading"      data-bttrlazyloading-xs='{"src": "img/720x200.gif", "width" : 720,  "height" : 200}'      data-bttrlazyloading-sm='{"src": "img/360x200.gif", "width" : 360,  "height" : 200}'      data-bttrlazyloading-md='{"src": "img/470x200.gif", "width" : 470,  "height" : 200}'      data-bttrlazyloading-lg='{"src": "img/570x200.gif", "width" : 570,  "height" : 200}'  />

Only one image size needed! BttrLazyLoading always try to load the biggest version of the image available. Therefore the following example will work on every screen too.

<img id="yourImageId" class="bttrlazyloading"      data-bttrlazyloading-md-src="img/455x350.gif"  />

项目主页：http://www.open-open.com/lib/view/home/1393249166505