后台传的图片流在前端展示图片

// 获取二维码图片
    getCodeImg() {
      this.getUUID();
      let UUID = window.sessionStorage.getItem("UUID");
      this.$axios
        .get("getImg", {
          responseType: "arraybuffer",
          params: { clientId: UUID }
        })
        .then(res => {
          return (
            "data:image/png;base64," +
            btoa(
              new Uint8Array(res.data).reduce(
                // String.fromCharCode() 可接受一个指定的 Unicode 值，然后返回一个字符串
                (data, byte) => data + String.fromCharCode(byte),
                ""
              )
            )
          );
        })
        .then(data => {
          this.imgUrl = data; //赋值给img标签的src属性
        });
    },

<img :src="imgUrl" alt="二维码图片" v-show="showCode" class="QRcode" />