基于文件下载的进度条

我将如何显示一个基于节点webkit中下载的文件的进度条？

var https = require('https'); var fs = require('fs'); var exec = require('child_process').exec; var file = fs.createWriteStream("update_setup.exe"); var len = 0; var request = https.get(url + 'appdata/update_setup.exe', function (response) { response.pipe(file); response.on('data', function (chunk) { file.write(chunk); len += chunk.length; var percent = (len / response.headers['content-length']) * 100; }); file.on('finish', function () { setTimeout(function () { win.close(); exec('update_setup.exe'); }, 1000); }); }); 

Answer 1

读取响应的content-length标头，并将其与已经下载的字节数量进行比较。

 var http = require('http'); var fs = require('fs'); var file = fs.createWriteStream('dest'); var len = 0; http.get(url, function(res) { res.on('data', function(chunk) { file.write(chunk); len += chunk.length; // percentage downloaded is as follows var percent = (len / res.headers['content-length']) * 100; }); res.on('end', function() { file.close(); }); file.on('close', function() { // the file is done downloading exec('update_setup.exe'); }); }); 

该代码检查收到的数据的长度并将其添加到len 。 将文件的总大小除以len ，再乘以100得到一个百分比。