代码通过move_uploaded_file（）函数实现文件上传功能，以及$_FILES的属性来判断文件的状态，再返回json数据显示在button下面，效果图如下：
代码如下：
前端：
实例
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
body{
font-family: microsoft yahei;
}
.box{
margin: 30px auto;
width: 450px;
background-color: #DCDCDC;
height: 140px;
border-radius: 5px;
text-align: center;
}
.box p{
text-align: center;
margin-left: 20px;
padding-top: 20px;
}
button{
margin: auto;
width: 70px;
height: 30px;
font-size: 13px;
border: none;
background-color:#1E90FF;
border-radius: 5px;
cursor: pointer;
color: #fff;
}
</style>
</head>
<body>
<div class="box">
<p>
上传文件：<input type="file" id="file">
</p>
<button id="upload">开始上传</button>
</div>
</body>
</html>
<script type="text/javascript" src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function () {
$('button').click(function () {
if($('#file').val().length==0){
$('#file').parent($('span').remove())
$('#upload').after('<span style="padding-left:10px; color: #ff0000;font-size: 14px;">没有选择文件！</span>')
}else{
var files=$("#file")[0].files[0]
var formdata = new FormData()
formdata.append('files',files)
$.ajax({
url:'upload.php',
type:'POST',
data:formdata,
dataType:'JSON',
processData:false,
contentType:false,
success:function (status) {
$('#upload').parent($('span').remove())
$('#upload').after('<br><span style="position:relative;top:10px; color:#008800;font-size: 14px;">'+status.msg+'</span>')
}
})
}
})
})
</script>运行实例 »
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后台：
实例
<?php
ini_set('date.timezone','Asia/Shanghai');
if($_SERVER['REQUEST_METHOD']=="POST"){
if(isset($_FILES['files'])){
$img_type=['image/jpg','image/jpeg','image/png'];
if(in_array($_FILES['files']['type'], $img_type)){
$_FILES["files"]["name"] = date('YmdHis').$_FILES["files"]["name"];
if(move_uploaded_file($_FILES["files"]["tmp_name"],"upload/". $_FILES["files"]["name"])){
echo json_encode(['msg'=>'上传成功！文件名是：'. $_FILES["files"]["name"]]);
} else {
echo json_encode(['msg'=>'上传失败']);
}
}else{
echo json_encode(['msg'=>'格式有误！']);
}
}else{
echo json_encode(['msg'=>'没有选择文件！']);
}
if($_FILES['files']['error']>0){
switch ($_FILES['files']['error']) {
case 1:
echo json_encode(['msg'=>'文件超过php.ini中的默认大小']);
break;
case 2:
echo json_encode(['msg'=>'文件超过表单设置大小']);
break;
case 3:
echo json_encode(['msg'=>'文件只有一部分上传']);
break;
case 4:
echo json_encode(['msg'=>'没有文件上传']);
break;
case 6:
echo json_encode(['msg'=>'没有临时文件夹']);
break;
case 8:
echo json_encode(['msg'=>'上传意外终止']);
break;
default:
echo json_encode(['msg'=>'未知错误']);
break;
}
}
}运行实例 »
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