微信小程序下载图片到本地 报错 saveImageToPhotosAlbum:fail invalid file type

不要使用默认的保存路径
wx.downloadFile 和 wx.saveImageToPhotosAlbum 的 filePath 使用自定义的

  saveToPhone() {
    const url = wx.env.USER_DATA_PATH + "/" + new Date().getTime().toString() + this.data.url.slice(this.data.url.lastIndexOf('.'))
    console.log(url)
    wx.showLoading({
      title: '保存中...'
    })
    wx.downloadFile({ //下载文件资源到本地
      url: this.data.url, // 网络图片的地址
      filePath: url,
      success: function (res) {
        console.log(res);
        //图片保存到本地

        if (res.statusCode === 200) {
          wx.saveImageToPhotosAlbum({
            filePath: url,
            success: function (data) {
              wx.hideLoading()
              wx.showToast({
                title: '保存成功',
                icon: 'success',
                duration: 2000
              })

              let fileMgr = wx.getFileSystemManager()
              fileMgr.unlink({
                filePath: url,
                success: () => {
                  console.log('删除缓存成功!')
                }
              })
            },
            fail: function (err) {
              if (err.errMsg === "saveImageToPhotosAlbum:fail auth deny" || err.errMsg === "saveImageToPhotosAlbum:fail:auth denied") {
                console.log("当初用户拒绝，再次发起授权")
                wx.showModal({
                  title: '提示',
                  content: '需要您授权保存相册',
                  showCancel: false,
                  success: () => {
                    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) {
              console.log(res);
              wx.hideLoading()
            }
          })
        }

      }
    })
  },