1. 程式人生 > >仿微信朋友圈圖片點選放大效果

仿微信朋友圈圖片點選放大效果

這兩天寫了個小專案,其中用到了點選一組圖片中的一張可以檢視它的放大版,用手向左滑動能看到下一張的這組圖片中的第二張的放大版。。。依次類推,單擊放大版的圖片實現關閉效果,對於js能力不太好的我只能找度娘,然後就發現了photoswiper.js,不得不說真的好用,下面我就簡單說下用法。
首先,和使用其他外掛一樣找到必須的資源也就是css,js等必須的檔案,然後引入它們,並且引入自己在專案中肯定會用到的基礎檔案比如jq.和自己寫的css檔案比如style.css這個名字是你自己取的,可隨意,最好結合專案取名。

<link rel="stylesheet" type="text/css"
href="css/photoswipe.css">
<link rel="stylesheet prefetch" href="css/default-skin/default-skin.css"> <link rel="stylesheet" type="text/css" href="css/style.css"> <script type="text/javascript" src="js/jquery.min.js"></script> <script src="js/photoswipe.js"></script>//實際應用時最好引入壓縮版min.js(css同理) <script
src="js/photoswipe-ui-default.min.js">
</script>

其次,在需要實現此效果的圖片組外層加入下面這些結構:

<div class="my-gallery" data-pswp-uid="1">
    <div>
        <a href="images/3.png" data-size="750x980">
            <img style="height:100%;" src="images/1.png">
        </a>
    </div>
<div> <a href="images/3.png" data-size="750x980"> <img style="height:100%;" src="images/2.png"> </a> </div> <div> <a href="images/3.png" data-size="750x980"> <img style="height:100%;" src="images/3.png"> </a> </div> </div>

其實最重要的就是class=”my-gallery” data-pswp-uid=”1”和也是和photoswiper.js產生關聯的鑰匙其中a標籤裡面的data-size是設定展示的放大圖的大小的,而href指向這個圖,一般是原圖。如果你想給展示的放大圖新增附加資訊,你可以在最外層div下再巢狀一層div,當然這個你可以依據設計需求自己改寫頁面結構在style.css中重置default-skin.css或photoswipe.css中的某些樣式或者書寫自己想要的樣式,但是上述的關鍵鑰匙必須存在。
然後,將下面這段程式碼完整的貼上到你的頁面中(這是放大版的結構設定以及一些小元件,比如分享按鈕,關閉按鈕等):

<div class="pswp" tabindex="-1" role="dialog" aria-hidden="true">
    <div class="pswp__bg"></div>
    <div class="pswp__scroll-wrap">
        <div class="pswp__container">
            <div class="pswp__item"></div>
            <div class="pswp__item"></div>
            <div class="pswp__item"></div>
        </div>
        <div class="pswp__ui pswp__ui--hidden">
            <div class="pswp__top-bar">
                <div class="pswp__counter"></div>
                <button class="pswp__button pswp__button--close" title="Close (Esc)"></button>
                <button class="pswp__button pswp__button--share" title="Share"></button>
                <button class="pswp__button pswp__button--fs" title="Toggle fullscreen"></button>
                <button class="pswp__button pswp__button--zoom" title="Zoom in/out"></button>
                <div class="pswp__preloader">
                    <div class="pswp__preloader__icn">
                        <div class="pswp__preloader__cut">
                            <div class="pswp__preloader__donut"></div>
                        </div>
                    </div>
                </div>
            </div>
            <div class="pswp__share-modal pswp__share-modal--hidden pswp__single-tap">
                <div class="pswp__share-tooltip"></div>
            </div>
            <button class="pswp__button pswp__button--arrow--left" title="Previous (arrow left)"></button>
            <button class="pswp__button pswp__button--arrow--right" title="Next (arrow right)"></button>
                <div class="pswp__caption">
                    <div class="pswp__caption__center"></div>
                </div>
            </div>
        </div>
    </div>

其次,將下面核心的js程式碼全部貼上過去(需要實現的小功能基本上都有,或者在api上找到相應的然後新增到引數裡即可,比如實現單擊放大的圖片就退回原來的小圖功能就是options裡面的tapToClose設定為true即可,如果不需要這個功能設定為false或者直接刪除這一行程式碼即可。):

var initPhotoSwipeFromDOM = function(gallerySelector) {

    // 解析來自DOM元素幻燈片資料(URL,標題,大小...)
    // (children of gallerySelector)
    var parseThumbnailElements = function(el) {
        var thumbElements = el.childNodes,
            numNodes = thumbElements.length,
            items = [],
            figureEl,
            linkEl,
            size,
            item,
            divEl;

        for(var i = 0; i < numNodes; i++) {

            figureEl = thumbElements[i]; // <figure> element

            // 僅包括元素節點
            if(figureEl.nodeType !== 1) {
                continue;
            }
            divEl = figureEl.children[0];
            linkEl = divEl.children[0]; // <a> element

            size = linkEl.getAttribute('data-size').split('x');

            // 建立幻燈片物件
            item = {
                src: linkEl.getAttribute('href'),
                w: parseInt(size[0], 10),
                h: parseInt(size[1], 10)
            };



            if(figureEl.children.length > 1) {
                // <figcaption> content
                item.title = figureEl.children[1].innerHTML; 
            }

            if(linkEl.children.length > 0) {
                // <img> 縮圖節點, 檢索縮圖網址
                item.msrc = linkEl.children[0].getAttribute('src');
            } 

            item.el = figureEl; // 儲存連結元素 for getThumbBoundsFn
            items.push(item);
        }

        return items;
    };

    // 查詢最近的父節點
    var closest = function closest(el, fn) {
        return el && ( fn(el) ? el : closest(el.parentNode, fn) );
    };

    // 當用戶點選縮圖觸發
    var onThumbnailsClick = function(e) {
        e = e || window.event;
        e.preventDefault ? e.preventDefault() : e.returnValue = false;

        var eTarget = e.target || e.srcElement;

        // find root element of slide
        var clickedListItem = closest(eTarget, function(el) {
            return (el.tagName && el.tagName.toUpperCase() === 'FIGURE');
        });

        if(!clickedListItem) {
            return;
        }

        // find index of clicked item by looping through all child nodes
        // alternatively, you may define index via data- attribute
        var clickedGallery = clickedListItem.parentNode,
            childNodes = clickedListItem.parentNode.childNodes,
            numChildNodes = childNodes.length,
            nodeIndex = 0,
            index;

        for (var i = 0; i < numChildNodes; i++) {
            if(childNodes[i].nodeType !== 1) { 
                continue; 
            }

            if(childNodes[i] === clickedListItem) {
                index = nodeIndex;
                break;
            }
            nodeIndex++;
        }



        if(index >= 0) {
            // open PhotoSwipe if valid index found
            openPhotoSwipe( index, clickedGallery );
        }
        return false;
    };

    // parse picture index and gallery index from URL (#&pid=1&gid=2)
    var photoswipeParseHash = function() {
        var hash = window.location.hash.substring(1),
        params = {};

        if(hash.length < 5) {
            return params;
        }

        var vars = hash.split('&');
        for (var i = 0; i < vars.length; i++) {
            if(!vars[i]) {
                continue;
            }
            var pair = vars[i].split('=');  
            if(pair.length < 2) {
                continue;
            }           
            params[pair[0]] = pair[1];
        }

        if(params.gid) {
            params.gid = parseInt(params.gid, 10);
        }

        return params;
    };

    var openPhotoSwipe = function(index, galleryElement, disableAnimation, fromURL) {
        var pswpElement = document.querySelectorAll('.pswp')[0],
            gallery,
            options,
            items;

        items = parseThumbnailElements(galleryElement);

        // 這裡可以定義引數
        options = {
          barsSize: { 
            top: 100,
            bottom: 100
          }, 
           fullscreenEl : false,
           //點選圖片關閉
           tapToClose: true,
            shareButtons: [
            {id:'wechat', label:'分享微信', url:'#'},
            {id:'weibo', label:'新浪微博', url:'#'},
            {id:'download', label:'儲存圖片', url:'{{raw_image_url}}', download:true}
            ],

            // define gallery index (for URL)
            galleryUID: galleryElement.getAttribute('data-pswp-uid'),

            getThumbBoundsFn: function(index) {
                // See Options -> getThumbBoundsFn section of documentation for more info
                var thumbnail = items[index].el.getElementsByTagName('img')[0], // find thumbnail
                    pageYScroll = window.pageYOffset || document.documentElement.scrollTop,
                    rect = thumbnail.getBoundingClientRect(); 

                return {x:rect.left, y:rect.top + pageYScroll, w:rect.width};
            }

        };

        // PhotoSwipe opened from URL
        if(fromURL) {
            if(options.galleryPIDs) {
                // parse real index when custom PIDs are used 
                for(var j = 0; j < items.length; j++) {
                    if(items[j].pid == index) {
                        options.index = j;
                        break;
                    }
                }
            } else {
                // in URL indexes start from 1
                options.index = parseInt(index, 10) - 1;
            }
        } else {
            options.index = parseInt(index, 10);
        }

        // exit if index not found
        if( isNaN(options.index) ) {
            return;
        }

        if(disableAnimation) {
            options.showAnimationDuration = 0;
        }

        // Pass data to PhotoSwipe and initialize it
        gallery = new PhotoSwipe( pswpElement, PhotoSwipeUI_Default, items, options);
        gallery.init();
    };

    // loop through all gallery elements and bind events
    var galleryElements = document.querySelectorAll( gallerySelector );

    for(var i = 0, l = galleryElements.length; i < l; i++) {
        galleryElements[i].setAttribute('data-pswp-uid', i+1);
        galleryElements[i].onclick = onThumbnailsClick;
    }

    // Parse URL and open gallery if it contains #&pid=3&gid=1
    var hashData = photoswipeParseHash();
    if(hashData.pid && hashData.gid) {
        openPhotoSwipe( hashData.pid ,  galleryElements[ hashData.gid - 1 ], true, true );
    }
    };

    // execute above function
    initPhotoSwipeFromDOM('.my-gallery');


//  $(".hairImg>div").each(function(){
//      $(this).height($(this).width());
//  });
    function more(obj,id) {
        if ($('#txt'+id).is(":hidden")) {
            $('#p'+id).hide();
            $('#txt'+id).show();
            obj.innerHTML='收起';
        } else {
            $('#p'+id).show();
            $('#txt'+id).hide();
            obj.innerHTML='全文';
        }
    }

最後,展示下我的demo效果圖:
設計原圖
點選裡面的任意一張小圖出現的效果(單擊圖片會回到第一張截圖的狀態)
好了,這就是所有的乾貨,希望對你們有所幫助。貌似photoswiper.js api裡面有更簡化的,小夥伴們也可以去讀一下api。相關檔案的下載地址可以去Github:點選這裡