SheetJs 导入数据

 <a (click)="import()">导入</a>
 <input #importExcelInput [hidden]="true" type="file" (change)="onFileChange($event)" multiple="false" />

 import() {
    let input = this.importExcelInput.nativeElement;
    input.value = '';
    input.click();
  }

  //导入
  async onFileChange(evt: any) {
    this.isTableLoading = true;
    let self = this;
    return new Promise(function (resolve, reject) {
      /* wire up file reader */
      const target: DataTransfer = <DataTransfer>evt.target;
      if (target.files.length !== 1) throw new Error('无法上传多个文件');
      const reader: FileReader = new FileReader();
      reader.readAsBinaryString(target.files[0]);
      let itemList: any[] = [];
      reader.onload = async (e: any) => {
        /* read workbook */
        const bstr: string = e.target.result;
        const wb: WorkBook = read(bstr, { type: 'binary' });
        /* grab first sheet */
        const wsname: string = wb.SheetNames[0];
        const ws: WorkSheet = wb.Sheets[wsname];
        const lengthStr = ws['!ref'].split(':')[1];
        const rowLength = parseInt(lengthStr.replace(/[^\d]/g, ' '));
        for (let index = 2; index <= rowLength; index++) {
          var entity: any = {};
          entity.name = ws[`A${index}`] ? ws[`A${index}`].v.toString() : null;
          entity.num = ws[`B${index}`] === undefined ? 0 : ws[`B${index}`].v;
          entity.amount = ws[`C${index}`] === undefined ? 0 : ws[`C${index}`].v;
          entity.taxRate = ws[`D${index}`] === undefined ? TaxRateEnum['13%'] : ws[`D${index}`].v;
          if (!entity.name) {
            self.notify.error('必填项存在为空!!!，请矫正后重试');
            self.isTableLoading = false;
            reject();
            break;
          }
          var reg = /^[0-9]*$/;
          var reg2 = /^(([0-9]+\.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0-9]*\.[0-9]+)|([0-9]*[1-9][0-9]*))$/;
          if (!reg.test(entity.num) || !reg2.test(entity.amount) || !reg2.test(entity.taxRate)) {
            self.notify.error('存在数字类型数据非法!!!，请矫正后重试');
            self.isTableLoading = false;
            reject();
            break;
          }

          itemList.push(entity);
          resolve(itemList);
        }
      };
    }).then(itemList => {
      //   console.log(itemList);
      this.service
        .getSparePartInfoByImport(itemList)
        .pipe(
          finalize(() => {
            this.isTableLoading = false;
          })
        )
        .subscribe(data => {
          this.notify.success('导入成功');
          var ls: any = [];
          var index = 0;
          if (this.dataList.length >= 1) {
            index = this.dataList[this.dataList.length - 1].index + 1;
          }
          data.map(i => {
            i.index = index;
            index++;
          });
          ls.push(...this.dataList);
          ls.push(...data);
          this.dataList = ls;
        });
    });
  }