把用户的头像上传，限制在2M以内 

代码

that.onChooseAvatar = (e) => {console.log('onChooseAvatar2', e);const avatarUrl = e.target.avatarUrl;let FileSystemManager = wx.getFileSystemManager()FileSystemManager.getFileInfo({"filePath": avatarUrl,success(res) {console.log('FileInfo-res', res)if (res.size > 1024 * 1024 * 2) {wx.showToast({title: '所选图片过大，请选择2M以内的图片',icon: 'none'})} else {let imgPath =`nhs/userUpload/avatarUrl/${wx.getStorageSync('userToken')}${new Date().getTime() + Math.floor(Math.random() * 150)}`uploadImage.uploadFile(avatarUrl, imgPath,function(result) {that.saveUserInfo({'avatarUrl': result})},function(result) {wx.hideLoading();})}},fail(err) {console.log('FileInfo-err', err)},})}