我有一个解析 Excel 文件的 Angular 服务,它看起来像这样:
import { Injectable } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import * as XLSX from 'xlsx';
type AOA = any[][]
@Injectable({
providedIn:'root'
})
export class BomParseService {
data: AOA = []
constructor()
{
}
parseExcel(excelFile)
{
/* wire up file reader */
const target: DataTransfer = <DataTransfer>(excelFile.target);
if (target.files.length !== 1) throw new Error('Cannot use multiple files');
const reader: FileReader = new FileReader();
reader.onload = (e: any) =>
{
/* read workbook */
const bstr: string = e.target.result;
const wb: XLSX.WorkBook = XLSX.read(bstr, { type: 'binary' });
/* grab first sheet */
const wsname: string = wb.SheetNames[0];
const ws: XLSX.WorkSheet = wb.Sheets[wsname];
/* save data */
this.data = <AOA>(XLSX.utils.sheet_to_json(ws, { header: 1 }));
console.log("BOM PARSE SERVICE LOG: " , this.data)
return this.data
};
reader.readAsBinaryString(target.files[0]);
}
如您所见,我正在尝试返回 this.data 的值。但是,当我尝试在组件中访问此值时,我存储该值的变量返回未定义。
async ReadExcel(event)
{
return new Promise<Object>((resolve, reject) =>
{
let excelContents = this.parser.parseExcel(event)
console.log(excelContents)
}
)}
parser 是引用服务的私有类。控制台日志excelContents
在控制台中产生 undefined 即使我认为它现在应该采用服务函数的返回值。我在这里遗漏了一些明显的东西吗?