Echarts下载图片

  base64ToBlob(code) {
      let parts = code.split(";base64,");
      let contentType = parts[0].split(":")[1];
      let raw = window.atob(parts[1]);
      let rawLength = raw.length;

      let uInt8Array = new Uint8Array(rawLength);

      for (let i = 0; i < rawLength; ++i) {
        uInt8Array[i] = raw.charCodeAt(i);
      }
      return new Blob([uInt8Array], { type: contentType });
    },
    saveAsImage() {
      let content = this.chart.getDataURL({
        backgroundColor:'#fff'
      });

      let aLink = document.createElement("a");
      let blob = this.base64ToBlob(content);

      let evt = document.createEvent("HTMLEvents");
      evt.initEvent("click", true, true);
      aLink.download = "line.png";
      aLink.href = URL.createObjectURL(blob);
      aLink.dispatchEvent(
        new MouseEvent("click", {
          bubbles: true,
          cancelable: true,
          view: window,
        })
      );
    },