展示 用xlsx库 导出excel，含多个sheet

        // 将workbook装化成blob对象
        function workbook2blob(workbook) {
          // 生成excel的配置项
          var wopts = {
            // 要生成的文件类型
            bookType: "xlsx",
            // // 是否生成Shared String Table，官方解释是，如果开启生成速度会下降，但在低版本IOS设备上有更好的兼容性
            bookSST: false,
            type: "binary"
          };
          var wbout = XLSX.write(workbook, wopts);
          // 将字符串转ArrayBuffer
          function s2ab(s) {
            var buf = new ArrayBuffer(s.length);
            var view = new Uint8Array(buf);
            for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xff;
            return buf;
          }
          var blob = new Blob([s2ab(wbout)], {
            type: "application/octet-stream"
          });
          return blob;
        }
  
        // 将blob对象创建bloburl，然后用a标签实现弹出下载框
        function openDownloadDialog(blob, fileName) {
          if (typeof blob == "object" && blob instanceof Blob) {
            blob = URL.createObjectURL(blob); // 创建blob地址
          }
          var aLink = document.createElement("a");
          aLink.href = blob;
          // HTML5新增的属性，指定保存文件名，可以不要后缀，注意，有时候 file:///模式下不会生效
          aLink.download = fileName || "";
          var event;
          if (window.MouseEvent) event = new MouseEvent("click");
          //   移动端
          else {
            event = document.createEvent("MouseEvents");
            event.initMouseEvent( "click", true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null );
          }
          aLink.dispatchEvent(event);
        }
        let sheet1data = [ { department: "行政部", count: 2 }, { department: "前端部", count: 2 } ];
        let sheet2data = [ { name: "张三", do: "整理文件" }, { name: "李四", do: "打印" } ];
        let sheet3data = [ { name: "张大人", do: "vue" }, { name: "李大人", do: "react" } ];
        var sheet1 = XLSX.utils.json_to_sheet(sheet1data);
        var sheet2 = XLSX.utils.json_to_sheet(sheet2data);
        var sheet3 = XLSX.utils.json_to_sheet(sheet3data);
  
        /* create a new blank workbook */
        var wb = XLSX.utils.book_new();
        XLSX.utils.book_append_sheet(wb, sheet1, "部门统计");
        XLSX.utils.book_append_sheet(wb, sheet2, "行政部");
        XLSX.utils.book_append_sheet(wb, sheet3, "前端部");
        const workbookBlob = workbook2blob(wb);
        // 点击下载
        document.querySelector('#export').onclick = function(){openDownloadDialog(workbookBlob, `部门统计.xlsx`);}