相关疑难解决方法(0)

任何人都可以提供一些示例代码来使用JavaScript读写文件吗？

我正在使用的业务应用程序angularJS.我的一个服务方法返回我byte[](包括PDF文件内容)现在我需要下载此文件作为PDF客户端机器使用JavaScript.

如何使用HTML5 Apis或任何JavaScript API？

我用过 window.atob(base64String)

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

但得到以下错误 Failed to execute 'atob' on 'Window': The string to be decoded is not correctly encoded.

我为此查看了多种资源，但是似乎没有一个能够回答我的问题。我的 React 应用程序中有一个名为 的本地 JSON 文件items.json。在该文件中，是我希望能够更新的对象列表。我尝试过使用fs，但这显然在 React 中不起作用，因为我收到了这个错误：

Unhandled Rejection (TypeError): fs.readFileSync is not a function

我想做的是，当代码获取新项目时，它会查看 JSON 文件以查看其name属性中是否存在具有匹配值的现有对象。如果存在，它会将该对象count属性增加 1，否则它会创建一个新对象，并将其附加到 JSON 文件中的列表中。这是我为此编写的代码。逻辑似乎很合理（尽管未经测试），但我不知道如何读取/写入数据。

let raw = fs.readFileSync("../database/items.json");
let itemList = JSON.parse(raw);
let found = false;
for (let item of itemList.averages) {
    if (item.name === this.state.data.item_name) {
        found = true;
        item.count += 1;
    }
}
if (!found) {
    let newItem = {
        name: this.state.data.item_name,
        count: 1,
    }
    itemList.averages.push(newItem);
}
let newRaw = JSON.stringify(itemList);
fs.writeFileSync("../database/items.json", …

我试图从一个html表单写入一个文件,但是javascript的写入部分没有做任何事情.

只有脚本的验证部分似乎正在工作.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<script LANGUAGE="JavaScript">
function Write(input1, input2)
{
    var fso =  new ActiveXObject("Scripting.FileSystemObject");  
    var s = fso.OpenTextFile("C:\\test.txt", true);
    s.WriteLine(input1 + "," + input2);
    s.Close();
}

function validateForm() {
    var x1=document.userform.pwd.value;
    var x2=document.userform.re_pwd.value;
    if (x2 == x1){
        Write(document.userform.user.value, document.userform.pwd.value);
    }
    else{alert("Passwords are not the same, Re-enter password");}
}
</SCRIPT>

<head>

    <link rel="stylesheet" href="css/screen.css" media="screen" />
</head>
<body>

<div id="container">

        <h2>Create a new account <?php echo "It works!"; ?></h2>
        <form id="form1" NAME="userform" …

我正在尝试了解有关为即将到来的项目处理文件的更多信息。当 onDrop 碰巧更改我正在上传的文件的内容时，我可以使用 react-dropzone 运行一个函数吗？例如，如果我要上传一个 Word 文档，上面写着“大家好”，我如何将内容更改为“嗨，尼克博士”？

在尝试进行更改之前，我曾尝试使用 filereader api 访问数据。我尝试在 async 函数的大括号打开后立即使用 filereader，但无法使其正常工作。

import React from 'react';
import Dropzone from 'react-dropzone';
import { graphql } from 'react-apollo';
import gql from 'graphql-tag';

const FileUpload = ({
    children, disableClick, channelId, mutate, style = {},
}) => (
    <Dropzone
        style={style}
        className="ignore"
        onDrop={async ([file]) => {
            const response = await mutate({
                variables: {
                    channelId,
                    file,
                },
            });
            console.log(response);
        }}
        disableClick={disableClick}
    >
        {children}
    </Dropzone>
);

const createFileMessageMutation = gql`
  mutation($channelId: Int!, $file: File) { …

如何在纯js（无节点）中编辑文件？我得到一个带有输入字段的文件，并像这样读取其文本：

var fileReader = new FileReader();
fileReader.readAsText(file);

fileReader.onload = function () {
    alert(this.result);
}

所以，非常简单。我尝试在网上查看如何使用 fileWriter 但没有成功。我只需要编辑该文件中的文本并保存它，该怎么办？

我有一个脚本(使用PhantomJS)来测试加载网页所需的时间.我想弄清楚的是如何写入将页面加载到.csv文件所花费的时间的结果.然后,如果我再次重新运行测试,它将另一个结果添加到.csv文件中.

码:

var page = require('webpage').create(),
    system = require('system'),
    t, address;
var pageLoadArray = [];
var csvContents = "";
fs = require('fs');

if (system.args.length === 1) {
    console.log('Usage: loadspeed.js <some URL>');
    phantom.exit(1);
} else {
    t = Date.now();
    address = system.args[1];
    page.open(address, function (status) {
        if (status !== 'success') {
            console.log('FAIL to load the address');
        } 
        else {
            t = Date.now() - t;
            console.log('Page title is ' + page.evaluate(function () {
                return document.title;
            }));

            if(t>7000){
                console.log('Loading time was too long... …

我正在开发一个简单的HTML/Javascript应用程序.此应用程序在文本区域中向用户显示随机文本消息.我有15-20个这样的短信,最多500个字符.我不想将这些消息保存在数据库中.我有两个场景 -

1. 我为每条消息提供了多个.txt文件,然后仅使用javascript读取随机txt文件并在textarea中显示文件的内容.
   
2. 用户在单独的文本区域中输入消息,按"保存"按钮,应创建该消息的新txt文件.

我一直在搜索如何在javascript中读/写文件,我发现这两篇文章 - 是否可以仅使用JavaScript将数据写入文件？以及如何使用JavaScript读取和写入文件.
但这些帖子是关于在客户端读取文件或从文件输入类型读取文件.

/sf/answers/1470888261/

这个建议是关于使用一些服务器端语言.
有没有办法只使用Javascript读取和写入txt文件.