PHP+Ajax implements refresh-free picture upload with progress bar

This article mainly introduces the example of PHP Ajax image upload without refresh with progress bar, and organizes the code of PHP image upload without refresh with progress bar in detail. If you need it, you can learn about it.

Project requirements: 1. PHP Ajax image upload without refresh with progress bar, 2. With progress bar. Required plugins: jquery.js, jquery.form.js.

Recently I am working on a mobile web project, which requires the use of the Ajax upload function. The project requires PHP to upload images without refreshing and with a progress bar. Let me talk about my implementation method and see the effect first. Figure

This example requires the use of jquery.js, jquery.form.js, which are included in the demo. You can download them at the bottom of the article.

The first step is to create the front-end page index.html

This section is the front-end display content. What needs to be explained here is that the input: file The label doesn't look very nice, so I hide it. And use an a tag .uploadbtn to call the click event of the file tag to open and select the file.

Note: When uploading files, the form attribute enctype must be set to: multipart/form-data

 

 
 
 
 
 

 

 
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 点击上传文件

Second step, Ajax submission part

This part is the submission part of Ajax. The process is as follows:

• At the beginning of submission, pass the beforeSend callback function Set the progress bar to be displayed, the width of the progress bar is 0%, and the progress value is 0%;

• During the upload process, use the data returned in real time by the uploadProgress callback function to change the width and progress of the progress bar. value.

• After the upload is successful, the uploaded data information (image name, size, address, etc.) is output through the success callback function and the image is output to the page for preview.

• Of course, if it fails, there is an error callback function to help you adjust the height.

The third step, back-end PHP code upload.php

The back-end processing code is PHP file upload, but some judgments need to be made when uploading, such as file format, file size, etc.

Note: The ajax return format above is json, so the json code for the image must be correctly standardized, otherwise a message indicating that the upload was unsuccessful will appear.

$picname = $_FILES['uploadfile']['name']; 
 $picsize = $_FILES['uploadfile']['size']; 
 if ($picname != "") { 
 if ($picsize > 2014000) { //限制上传大小 
 echo '{"status":0,"content":"图片大小不能超过2M"}';
 exit; 
 } 
 $type = strstr($picname, '.'); //限制上传格式 
 if ($type != ".gif" && $type != ".jpg" && $type != "png") {
 echo '{"status":2,"content":"图片格式不对！"}';
 exit; 
 }
 $rand = rand(100, 999); 
 $pics = uniqid() . $type; //命名图片名称 
 //上传路径 
 $pic_path = "images/". $pics; 
 move_uploaded_file($_FILES['uploadfile']['tmp_name'], $pic_path); 
 } 
 $size = round($picsize/1024,2); //转换成kb 
 echo '{"status":1,"name":"'.$picname.'","url":"'.$pic_path.'","size":"'.$size.'","content":"上传成功"}';

Demo download: php-ajax-upload_jb51.rar

The above is the entire content of this article, I hope it will help everyone learn Helps.

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