微信小程序的分享功能，在最新版库的ide上已经不能拿到分享回调了，官方api也删除了对应的回调函数，看样子是砍掉了，不过真机测试还是可以的，话不多说，上代码：

onLoad: function(options) {
    wx.showShareMenu({
            //只有拥有 shareTicket 才能拿到群信息，用户每次转发都会生成对应唯一的shareTicket 。
            withShareTicket: true
        });
},
onShareAppMessage: function(res) {
        var _this = this;
        console.log(res);
        if (res.from === 'button') {
            // 来自页面内转发按钮
            _this.data.shareBtn = true;
        } else {
            //来自右上角转发
            _this.data.shareBtn = false;
        }
        return {
            title: '自定义转发标题',
            path: 'pages/index/index',
            complete: function(res) {
                console.log(res);
                if (res.errMsg == 'shareAppMessage:ok') {
                    //分享为按钮转发
                    if (_this.data.shareBtn) {
                        //判断是否分享到群
                        if (res.hasOwnProperty('shareTickets')) {
                            console.log(res.shareTickets[0]);
                            //分享到群
                            _this.data.isshare = 1;
                        } else {
                            // 分享到个人
                            _this.data.isshare = 0;
                        }
                    }
                } else {
                    wx.showToast({
                        title: '分享失败',
                    })
                    _this.data.isshare = 0;
                }
            },
        }
    }