每次使用 php 更新时，我不知道如何推送进度。为了清楚起见，我会写一个例子。

jQuery:

function uploadMovieDownload(link){
    $.post("php/downloadmovie.php", { source:link }, function(json){ console.log(json); });
}

uploadMovieDownload(url);

PHP (php/downloadmovie.php):

session_start();
ob_start();
date_default_timezone_set("Europe/Bucharest");
ini_set('display_errors',true);

require_once(dirname(__FILE__)."/functions.php");


$url = $_POST['source'];
$headers = getHeaders($url);
$url = $headers['url'];
$path = dirname(__FILE__)."/temp/test.mp4";

$fp = fopen ($path, 'w+');
$ch = curl_init();
curl_setopt( $ch, CURLOPT_URL, $url );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, false );
curl_setopt( $ch, CURLOPT_PROGRESSFUNCTION, 'progress' );
curl_setopt( $ch, CURLOPT_NOPROGRESS, false );
curl_setopt( $ch, CURLOPT_BINARYTRANSFER, true );
curl_setopt( $ch, CURLOPT_SSL_VERIFYPEER, false );
curl_setopt( $ch, CURLOPT_CONNECTTIMEOUT, 100 );
curl_setopt( $ch, CURLOPT_FILE, $fp );
curl_exec( $ch );
curl_close( $ch );
fclose( $fp );


function progress($resource,$download_size, $downloaded, $upload_size, $uploaded){
    if($download_size > 0) echo $downloaded / $download_size  * 100;
    ob_flush();
    flush();
}

echo "Done";
ob_flush();
flush();

我遇到的问题是它在完成后返回进度，而不是在下载时推送它。如果您有任何建议，请提前致谢。

最佳答案

使用这种方法，您会遇到各种缓存问题，php 输出缓冲吗？你会遇到问题。你在网络服务器后面，ala nginx/apache/lighthttp/anything？你会遇到问题。是浏览器缓存输出？ (所有主流浏览器都这样做)，你会遇到问题。

我建议一个不会有这些问题的替代方案:使用 $_SESSION 来存储下载百分比，并使用 XMLHttpRequests 查询百分比(实际上通过 WebSockets 查询百分比将是最佳的，无滞后，使用更少的带宽等，但很多更难实现)

下载电影.php

<?php 
require_once(dirname(__FILE__)."/functions.php");


$url = $_POST['source'];
$headers = getHeaders($url);
$url = $headers['url'];
//after validation of input
session_start();
$_SESSION['download_percentage']=0.0;//initialize it
session_write_close();
fastcgi_finish_request();//or if you're not using fcgi, some equivalent..

$path = dirname(__FILE__)."/temp/test.mp4";

$fp = fopen ($path, 'w+');
$ch = curl_init();
curl_setopt( $ch, CURLOPT_URL, $url );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, false );
curl_setopt( $ch, CURLOPT_PROGRESSFUNCTION, 'progress' );
curl_setopt( $ch, CURLOPT_NOPROGRESS, false );
curl_setopt( $ch, CURLOPT_BINARYTRANSFER, true );
curl_setopt( $ch, CURLOPT_SSL_VERIFYPEER, false );
curl_setopt( $ch, CURLOPT_CONNECTTIMEOUT, 100 );
curl_setopt( $ch, CURLOPT_FILE, $fp );
curl_exec( $ch );
curl_close( $ch );
fclose( $fp );


function progress($resource,$download_size, $downloaded, $upload_size, $uploaded){
    $percentage=$download_size==0? 0.0 : (($downloaded/$download_size)*100);
    session_start();
    $_SESSION['download_percentage']=$percentage;
    session_write_close();
}

getProgress.xhr.php

<?php 
if(""===session_id()){
session_start();
}
echo $_SESSION['download_percentage']??'?';

然后在浏览器中监控进度:

(function checkProgress() {
    "use strict";
    var xhr = new XMLHttpRequest();
    xhr.open("GET", "getProgress.xhr.php");
    xhr.addEventListener("readystatechange", function(ev) {
        var xhr = ev.target;
        if (xhr.readyState !== 4) {
            return;
        }
        console.log(xhr.responseText + " percent downloaded!");
        if (xhr.responseText === "100") {
            return; /*stop checking for progress when its finished*/
        }
        setTimeout(checkProgress, 1000); //<<check for progress every 1 second

    });
    xhr.send();
})();

重要编辑:正如@drew010 所指出的，没有 session_write_close();session_start(); 它就无法工作；每次 curl 更新值时，修复该值。

关于javascript - 使用jquery的PHP cURL下载进度，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/28241058/