定义分享时的缩略图、链接、标题、摘要确实是通过WeixinJSBridge实现的。

参考腾讯微生活的页面：（略去了跟此需求无关的代码，仅供参考）

<script>var imgUrl = ‘http://qqfood.tc.qq.com/meishio/16/4585bf7c-be04-420f-ac8a-2dba61a7561f/0‘;var lineLink = ‘http://life.qq.com/weixin/r/lottery/13826036970196242008#wechat_redirect‘;var descContent = "万达狂欢节, 夺宝幸运星大抽奖活动开始啦！";var shareTitle = ‘万达狂欢节‘;var appid = ‘wxc9937e3a66af6dc8‘;function shareFriend() {    WeixinJSBridge.invoke(‘sendAppMessage‘,{                            "appid": appid,                            "img_url": imgUrl,                            "img_width": "640",                            "img_height": "640",                            "link": lineLink,                            "desc": descContent,                            "title": shareTitle                            }, function(res) {                            _report(‘send_msg‘, res.err_msg);                            })}function shareTimeline() {    WeixinJSBridge.invoke(‘shareTimeline‘,{                            "img_url": imgUrl,                            "img_width": "640",                            "img_height": "640",                            "link": lineLink,                            "desc": descContent,                            "title": shareTitle                            }, function(res) {                            _report(‘timeline‘, res.err_msg);                            });}function shareWeibo() {    WeixinJSBridge.invoke(‘shareWeibo‘,{                            "content": descContent,                            "url": lineLink,                            }, function(res) {                            _report(‘weibo‘, res.err_msg);                            });}// 当微信内置浏览器完成内部初始化后会触发WeixinJSBridgeReady事件。document.addEventListener(‘WeixinJSBridgeReady‘, function onBridgeReady() {        // 发送给好友        WeixinJSBridge.on(‘menu:share:appmessage‘, function(argv){            shareFriend();            });        // 分享到朋友圈        WeixinJSBridge.on(‘menu:share:timeline‘, function(argv){            shareTimeline();            });        // 分享到微博        WeixinJSBridge.on(‘menu:share:weibo‘, function(argv){            shareWeibo();            });        }, false);</script>

微信分享朋友圈的标题和图片