base64文件下载

let blob = this.base64ToBlob(data); //base64编码
          var evt = document.createEvent("HTMLEvents");
          evt.initEvent("click", true, true);
          //initEvent 不加后两个参数在FF下会报错 （事件类型，是否冒泡，是否阻止浏览器的默认行为）
          let aLink = document.createElement("a");
          aLink.download = obj.cName; //文件名
          aLink.href = URL.createObjectURL(blob);
          aLink.click();

// base64转blob
 base64ToBlob(code) {
      var parts = code.split(";base64,");
      var contentType = parts[0].split(":")[1];
      var raw = window.atob(parts[1]);
      var rawLength = raw.length;
      var uInt8Array = new Uint8Array(rawLength);
      for (var i = 0; i < rawLength; ++i) {
        uInt8Array[i] = raw.charCodeAt(i);
      }
      return new Blob([uInt8Array], {
        type: contentType,
      });
    },