图片下载并发处理

当一个页面中有很多图片需要下载的时候，同时下载会产生下载超时问题，用到下面方法，小白路过，欢迎多提宝贵意见

// 下载图片
  async downImage(value: any) {
    let imgRes = "";
    var URL = "/hcm/img/down?fileName=" + value.imageName;
    await this.$httpService.postData({}, URL).then((res: any) => {
      // console.log("res", res);
      if (res.code == 0) {
        this.imgurl = res.data;
      }
      imgRes = res.msg;
    });
    return imgRes;
  }

  getImg(list: any) {
    // let iN = 1;
    if (this.iN == 1 && list.length) {
      this.arrList = list.slice(0, 2);
    } else if (this.iN > 1 && list.length > this.iN) {
      let arr: any = list[this.iN];
      this.arrList = [arr];
    }
    if (list.length > this.iN || (list.length == 1 && this.iN == 1)) {
      this.arrList.map(async (value: any) => {
        let res = await this.downImage(value);
        if (res) {
          this.iN++;
        }
        this.getImg(list);
      });
    }
  }