1、xhtml代码

长按保存：

 

2、Js代码

baocun: function (e) {        wx.showModal({            title: '提示',            content: '确定要保存这张图片吗？',            success: function (res) {                if (res.confirm) {                    console.log('用户点击确定')                    wx.getImageInfo({                        src: 'xxxxxxx',                        success: function (res) {                            console.log(res);                            var path = res.path;                            wx.saveImageToPhotosAlbum({                                filePath: path,                                success: function (res) {                                    console.log('图片已保存');                                },                                fail: function (res) {                                    console.log('保存失败');                                }                            })                        }                    });                } else if (res.cancel) {                    console.log('用户点击取消')                }            }        })    },

 

详情可参考