二进制流转base64传送门https://blog.csdn.net/m0_60067716/article/details/124606097

 二进制流转base64这里就不介绍啦，可以看我上面的文章。

base64转图片核心代码

• imgSrc：就是base64地址哈

   saveImg() {
      var base64 = this.imgSrc.toString(); // imgSrc 就是base64哈
      var byteCharacters = atob(
        base64.replace(/^data:image\/(png|jpeg|jpg);base64,/, "")
      );
      var byteNumbers = new Array(byteCharacters.length);
      for (var i = 0; i < byteCharacters.length; i++) {
        byteNumbers[i] = byteCharacters.charCodeAt(i);
      }
      var byteArray = new Uint8Array(byteNumbers);
      var blob = new Blob([byteArray], {
        type: undefined,
      });
      var aLink = document.createElement("a");
      aLink.download = "图片名称.jpg"; //这里写保存时的图片名称
      aLink.href = URL.createObjectURL(blob);
      aLink.click();
    },

完整代码

<template>
  <div class="app">
    <img :src="imgSrc" alt="图片" />
    <button @click="saveImg">点击保存图片</button>
  </div>
</template>
<script>
import axios from "axios";
export default {
  name: "app",
  data() {
    return {
      imgSrc: "",
    };
  },
  methods: {
    // 二进制流转换为base64 格式。
    getBase64(data) {
      const blob = new Blob([data], { type: "image/jpg" }); //类型一定要写！！！
      return new Promise((resolve, reject) => {
        const reader = new FileReader();
        reader.readAsDataURL(blob);
        reader.onload = () => resolve(reader.result);
        reader.onerror = (error) => reject(error);
      });
    },
    // base64 保存图片
    saveImg() {
      var base64 = this.imgSrc.toString(); // imgSrc 就是base64哈
      var byteCharacters = atob(
        base64.replace(/^data:image\/(png|jpeg|jpg);base64,/, "")
      );
      var byteNumbers = new Array(byteCharacters.length);
      for (var i = 0; i < byteCharacters.length; i++) {
        byteNumbers[i] = byteCharacters.charCodeAt(i);
      }
      var byteArray = new Uint8Array(byteNumbers);
      var blob = new Blob([byteArray], {
        type: undefined,
      });
      var aLink = document.createElement("a");
      aLink.download = "图片名称.jpg"; //这里写保存时的图片名称
      aLink.href = URL.createObjectURL(blob);
      aLink.click();
    },
  },

  mounted() {
    //网上随便找的图片
    const url =
      "https://img0.baidu.com/it/u=73689209,3130028231&fm=253&fmt=auto&app=138&f=JPEG";
    axios
      .get(url, {
        responseType: "blob", //一定要传！！！
      })
      .then((res) => {
        console.log(res.data, "二进制流");
        this.getBase64(res.data).then((binary) => {
          console.log(binary, "base64");
          this.imgSrc = binary;
        });
      });
  },
};
</script>