Ionic | TypeError | fs.createWriteStream不是函数

Z时代
2024-01-10
分类：问答

我想创建一个示例excel文件，但我得到错误'fs.createWriteStream不是一个函数'。下面是代码来创建文件 -Ionic | TypeError | fs.createWriteStream不是函数

import { Component } from '@angular/core'; 
import { NavController, Platform } from 'ionic-angular'; 
import * as Excel from "exceljs/dist/exceljs.js"; 
@Component({ 
    selector: 'page-home', 
    templateUrl: 'home.html' 
}) 
export class HomePage { 
    constructor(platform: Platform) { 
    platform.ready().then(() => { 
     this.createSheetUsingExcelJs(); 
    }); 
    } 
    ionViewDidLoad() { 
    } 
    createSheetUsingExcelJs() { 
    let workbook = new Excel.Workbook(); 
    var worksheet = workbook.addWorksheet('My Sheet'); 
    worksheet.columns = [ 
     { header: 'Id', key: 'id', width: 10 }, 
     { header: 'Name', key: 'name', width: 32 }, 
     { header: 'D.O.B.', key: 'DOB', width: 10 } 
    ]; 
    worksheet.addRow({ id: 1, name: 'Ionic Android', dob: new Date(1970, 1, 1) }); 
    worksheet.addRow({ id: 2, name: 'Ionic iOS', dob: new Date(1965, 1, 7) }); 
    var tempFilePath = 'C:/Users/mahmad/Downloads/temp.xlsx'; 
    console.log(workbook); 
    workbook.xlsx.writeFile('temp.xlsx').then(function() { 
     console.log('file is written'); 
    }); 
    } 
}

请提出一个解决方案来解决这个问题

回答：

import * as Excel from "exceljs/dist/exceljs.js";

从JavaScript文件导入打字稿，您需要使用图书馆的类型定义文件。

它在npm可用。

务必：

npm i @types/exceljs --save-dev

为了导入：

import * as Excel from 'exceljs';

您可以在 “DefinitelyTyped” 测试文件repo

回答：

最后，任务是通过使用ts-xlsx library做检查样本。下面是我的代码 -

import { Component, Injectable } from '@angular/core'; 
import { NavController, Platform } from 'ionic-angular'; 
import * as XLSX from 'ts-xlsx'; 
import { File } from '@ionic-native/file'; 
import { EmailComposer } from '@ionic-native/email-composer'; 
declare var cordova: any; 
declare var window; 
@Component({ 
    selector: 'page-home', 
    templateUrl: 'home.html', 
    providers: [File] 
}) 
@Injectable() 
export class HomePage { 
    sheetNames: string[] = [] 
    sheets: any; 
    constructor(public emailComposer: EmailComposer, platform: Platform, public file: File) { 
    var objects = [["Header 1", "Header 2", "Header 3"], ["Value 1 1", "Value 1 2", "Value 1 3"], ["Value 2 1", "Value 2 2", "Value 2 3"]]; 
    platform.ready().then(() => { 
     console.log(cordova.file.externalCacheDirectory + "report.xlsx"); 
     this.createXSLX(objects); 
     this.sendEmail(cordova.file.externalCacheDirectory + "report.xlsx"); 
    }); 
    } 
    createXSLX(data: any) { 
    var pathFile = ""; 
    var fileName = "report.xlsx"; 
    let ws_name = "OrderDetails"; 
    let wb: XLSX.IWorkBook = { 
     SheetNames: [], 
     Sheets: {}, 
     Props: {} 
    }; 
    let ws = this.sheet_from_array_of_arrays(data, {}); 
    /* add worksheet to workbook */ 
    wb.SheetNames.push(ws_name); 
    wb.Sheets[ws_name] = ws; 
    let wbout = XLSX.write(wb, { bookType: 'xlsx', type: 'binary' }); 
    let xslxBlob = new Blob([this.s2ab(wbout)], { type: "application/octet-stream" }); 
    pathFile = cordova.file.externalCacheDirectory; 
    this.file.writeFile(pathFile, fileName, xslxBlob); 
    }  
    sendEmail(data) {  
    this.emailComposer.isAvailable().then((available: boolean) => { 
     if (available) { 
     //Now we know we can send 
     } 
    }); 
    let email = { 
     to: '', 
     attachments: [data], 
     subject: 'XLSX File', 
     body: 'How are you? Nice greetings from Leipzig', 
     isHtml: true 
    }; 
    // Send a text message using default options 
    this.emailComposer.open(email); 
    } 
    datenum(v, date1904): any { 
    if (date1904) v += 1462; 
    let epoch: any = Date.parse(v); 
    return (epoch - new Date(Date.UTC(1899, 11, 30)).getTime())/(24 * 60 * 60 * 1000); 
    } 
    sheet_from_array_of_arrays(data, opts) { 
    let ws = {}; 
    let range = { s: { c: 10000000, r: 10000000 }, e: { c: 0, r: 0 } }; 
    for (let R = 0; R != data.length; ++R) { 
     for (let C = 0; C != data[R].length; ++C) { 
     if (range.s.r > R) range.s.r = R; 
     if (range.s.c > C) range.s.c = C; 
     if (range.e.r < R) range.e.r = R; 
     if (range.e.c < C) range.e.c = C; 
     let cell: any = { v: data[R][C] }; 
     if (cell.v == null) continue; 
     let cell_ref = XLSX.utils.encode_cell({ c: C, r: R }); 
     if (typeof cell.v === 'number') cell.t = 'n'; 
     else if (typeof cell.v === 'boolean') cell.t = 'b'; 
     else if (cell.v instanceof Date) { 
      cell.t = 'n'; 
      //cell.z = XLSX.SSF._table[14]; 
      cell.v = this.datenum(cell.v, null); 
     } 
     else cell.t = 's'; 
     ws[cell_ref] = cell; 
     } 
    } 
    if (range.s.c < 10000000) ws['!ref'] = XLSX.utils.encode_range(range.s, range.e); 
    return ws; 
    } 
    s2ab(s) { 
    let buf = new ArrayBuffer(s.length); 
    let view = new Uint8Array(buf); 
    for (let i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF; 
    return buf; 
    } 
}