Backend DevelopmentPHP TutorialPHP file upload code implements native JS example of uploading large files to display progress barPHP file upload code implements native JS example of uploading large files to display progress bar
This article mainly introduces in detail the progress bar of large file upload in JS native and the key code of PHP file upload. It has certain reference value. Interested friends can refer to it
JS native Uploading large files displays a progress bar. PHP uploads files for your reference. The specific content is as follows
Modify the required size in php.ini:
upload_max_filesize = 8M
post_max_size = 10M
memory_limit = 20M
<!DOCTYPE html>
<html>
<head>
<title>原生JS大文件显示进度条</title>
<meta charset="UTF-8">
<style type="text/css">
#parent{position: relative;width: 500px;height:20px;border:1px solid #ccc;display: none;border-radius:20px}
#child{position: absolute;width:0%;height:20px;background: #5FB878;display: none;line-height: 20px;color: #ffffff;font-size: 12px;border-radius:20px}
</style>
<script type="text/javascript">
function $(id){
return document.getElementById(id);
}
</script>
</head>
<body>
<form action="" method="post">
<p id="parent">
<p id="child"></p>
</p>
<p>上传文件:<input type="file" name="file"></p>
<p><input type="submit" value="提交" id="submit"></p>
</form>
<script type="text/javascript">
var oForm = document.getElementsByTagName('form')[0];
var oSubmit = $('submit');
//如果多个人同时提交这个表单的时候，由于是异步的请求，互不影响
oSubmit.onclick = function(){
try{
var xhr = new XMLHttpRequest();
}catch(e){
var xhr = new ActiveXObject("Msxml2.XMLHTTP");
}
xhr.upload.onprogress = function(e){
var ev = e || window.event;
var percent = Math.floor((ev.loaded / ev.total)*100);
// console.log(percent);
//将百分比显示到进度条
$('parent').style.display = 'block';
$('child').style.display = 'block';
//将上传进度的百分比显示到child里面
$('child').style.width = percent+'%';
$('child').style.textAlign = 'center';
$('child').innerHTML = percent+'%';
//判断如果百分比到达100%时候，隐藏掉
if(percent==100){
$('parent').style.display = 'none';
$('child').style.display = 'none';
}
}
xhr.open('post','progress.php',true);
var form = new FormData(oForm);
xhr.send(form);
xhr.onreadystatechange = function(){
if(xhr.readyState==4 && xhr.status==200){
eval("var obj ="+xhr.responseText);
if(obj.status){
alert('上传成功');
}else{
alert('上传失败');
}
}
}
//阻止表单提交
return false;
}
</script>
</body>
</html><?php
//开始上传
//注意：文件是windows系统的文件，采用的gbk编码，php文件使用的是utf-8编码
//我们不能直接修改文件的编码，只能临时修改一下php的编码
$dst_file = $_FILES['file']['name'];
$dst_file = iconv('utf-8', 'gbk', $dst_file);
if(move_uploaded_file($_FILES['file']['tmp_name'],$dst_file)){
$data['status'] = 1;
}else{
$data['status'] = 0;
}
echo json_encode($data);The above is the detailed content of PHP file upload code implements native JS example of uploading large files to display progress bar. For more information, please follow other related articles on the PHP Chinese website!
How can you prevent session fixation attacks?Apr 28, 2025 am 12:25 AMEffective methods to prevent session fixed attacks include: 1. Regenerate the session ID after the user logs in; 2. Use a secure session ID generation algorithm; 3. Implement the session timeout mechanism; 4. Encrypt session data using HTTPS. These measures can ensure that the application is indestructible when facing session fixed attacks.
How do you implement sessionless authentication?Apr 28, 2025 am 12:24 AMImplementing session-free authentication can be achieved by using JSONWebTokens (JWT), a token-based authentication system where all necessary information is stored in the token without server-side session storage. 1) Use JWT to generate and verify tokens, 2) Ensure that HTTPS is used to prevent tokens from being intercepted, 3) Securely store tokens on the client side, 4) Verify tokens on the server side to prevent tampering, 5) Implement token revocation mechanisms, such as using short-term access tokens and long-term refresh tokens.
What are some common security risks associated with PHP sessions?Apr 28, 2025 am 12:24 AMThe security risks of PHP sessions mainly include session hijacking, session fixation, session prediction and session poisoning. 1. Session hijacking can be prevented by using HTTPS and protecting cookies. 2. Session fixation can be avoided by regenerating the session ID before the user logs in. 3. Session prediction needs to ensure the randomness and unpredictability of session IDs. 4. Session poisoning can be prevented by verifying and filtering session data.
How do you destroy a PHP session?Apr 28, 2025 am 12:16 AMTo destroy a PHP session, you need to start the session first, then clear the data and destroy the session file. 1. Use session_start() to start the session. 2. Use session_unset() to clear the session data. 3. Finally, use session_destroy() to destroy the session file to ensure data security and resource release.
How can you change the default session save path in PHP?Apr 28, 2025 am 12:12 AMHow to change the default session saving path of PHP? It can be achieved through the following steps: use session_save_path('/var/www/sessions');session_start(); in PHP scripts to set the session saving path. Set session.save_path="/var/www/sessions" in the php.ini file to change the session saving path globally. Use Memcached or Redis to store session data, such as ini_set('session.save_handler','memcached'); ini_set(
How do you modify data stored in a PHP session?Apr 27, 2025 am 12:23 AMTomodifydatainaPHPsession,startthesessionwithsession_start(),thenuse$_SESSIONtoset,modify,orremovevariables.1)Startthesession.2)Setormodifysessionvariablesusing$_SESSION.3)Removevariableswithunset().4)Clearallvariableswithsession_unset().5)Destroythe
Give an example of storing an array in a PHP session.Apr 27, 2025 am 12:20 AMArrays can be stored in PHP sessions. 1. Start the session and use session_start(). 2. Create an array and store it in $_SESSION. 3. Retrieve the array through $_SESSION. 4. Optimize session data to improve performance.
How does garbage collection work for PHP sessions?Apr 27, 2025 am 12:19 AMPHP session garbage collection is triggered through a probability mechanism to clean up expired session data. 1) Set the trigger probability and session life cycle in the configuration file; 2) You can use cron tasks to optimize high-load applications; 3) You need to balance the garbage collection frequency and performance to avoid data loss.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
WebStorm Mac version
Useful JavaScript development tools
SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
Notepad++7.3.1
Easy-to-use and free code editor
VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft
