button class='btn'  bindtap='postSave'保存到本地相册/button

postSave(e) {    wx.showLoading({      title: '保存中...'    })    wx.downloadFile({      url: 'http://xxx.com/poster.png',      success: function (res) {        //图片保存到本地        wx.saveImageToPhotosAlbum({          filePath: res.tempFilePath,          success: function (data) {            wx.hideLoading()            wx.showModal({              title: '提示',              content: '您的推广海报已存入手机相册，赶快分享给好友吧',              showCancel:false,            })          },          fail: function (err) {            if (err.errMsg === "saveImageToPhotosAlbum:fail:auth denied" || err.errMsg === "saveImageToPhotosAlbum:fail auth deny") {              // 这边微信做过调整，必须要在按钮中触发，因此需要在弹框回调中进行调用              wx.showModal({                title: '提示',                content: '需要您授权保存相册',                showCancel: false,                success:modalSuccess={                  wx.openSetting({                    success(settingdata) {                      console.log("settingdata", settingdata)                      if (settingdata.authSetting['scope.writePhotosAlbum']) {                        wx.showModal({                          title: '提示',                          content: '获取权限成功,再次点击图片即可保存',                          showCancel: false,                        })                      } else {                        wx.showModal({                          title: '提示',                          content: '获取权限失败，将无法保存到相册哦~',                          showCancel: false,                        })                      }                    },                    fail(failData) {                      console.log("failData",failData)                    },                    complete(finishData) {                      console.log("finishData", finishData)                    }                  })                }              })            }          },          complete(res) {            wx.hideLoading()          }        })      }    })  }