wx.getSetting({
      success: (res) => {
        if (!res.authSetting['scope.writePhotosAlbum']) {
          
          wx.authorize({
            scope: 'scope.writePhotosAlbum',
            success: () => {
              // 同意授权
            },
            fail: (res) => {
              // 无法唤醒设置
              wx.openSetting()
            }
          })
        } else {
          // 已经授权了
        }
      },
      fail: (res) => {
        console.log(res);
      }
    })