在网上看到一个比较好的多文件上传类，自己改良了下，顺便用js实现了多文件浏览，php文件上传原理都是相同的，多文件上传也只是进行了循环上传而已，当然你也可以使用swfupload进行多文件上传！
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script language="javascript" type="text/javascript">
function AddInput(){var input=document.createElement('input');//创建一个input节点var br=document.createElement('br');//创建一个br节点input.setAttribute('type','file');//设置input节点type属性为fileinput.setAttribute('name','files[]');//设置input节点name属性为files[]，以 数组的方式传递给服务器端document.myForm.appendChild(br);//把节点添加到form1表单中document.myForm.appendChild(input);
}
</script>
</head>
<body>
<?php
/** 尊重作者：mckee 来自www.phpddt.com* 可同时处理用户多个上传文件。效验文件有效性后存储至指定目录。* 可返回上传文件的相关有用信息供其它程序使用。（如文件名、类型、大小、保存路径）*/
class UploadFile {protected $user_post_file = array(); //用户上传的文件protected $save_file_path; //存放用户上传文件的路径protected $max_file_size; //文件最大尺寸protected $last_error; //记录最后一次出错信息//默认允许用户上传的文件类型protected $allow_type = array('gif', 'jpg', 'png', 'zip', 'rar', 'txt', 'doc', 'pdf','docx');protected $final_file_path; //最终保存的文件名protected $save_info = array(); //返回一组有用信息，用于提示用户。/*** 构造函数*/function __construct($file, $path, $size = 2097152, $type = '') {$this->user_post_file = $file;if(!is_dir($path)){ //存储路径文件不存在就创建mkdir($path);chmod($path,0777);}$this->save_file_path = $path;$this->max_file_size = $size; //如果用户不填写文件大小，则默认为2M.if ($type != '')$this->allow_type = $type;
}/*** 存储用户上传文件，检验合法性通过后，存储至指定位置。*/function upload() {for ($i = 0; $i < count($this->user_post_file['name']); $i++) {//如果当前文件上传功能，则执行下一步。if ($this->user_post_file['error'][$i] == 0) {//取当前文件名、临时文件名、大小、扩展名，后面将用到。$name = $this->user_post_file['name'][$i];$tmpname = $this->user_post_file['tmp_name'][$i];$size = $this->user_post_file['size'][$i];$mime_type = $this->user_post_file['type'][$i];$type = $this->getFileExt($this->user_post_file['name'][$i]);//检测当前上传文件大小是否合法。if (!$this->checkSize($size)) {$this->last_error = "The file size is too big. File name is: ".$name;$this->halt($this->last_error);continue;}//检测当前上传文件扩展名是否合法。if (!$this->checkType($type)) {$this->last_error = "Unallowable file type: .".$type." File name is: ".$name;$this->halt($this->last_error);continue;}//检测当前上传文件是否非法提交。if(!is_uploaded_file($tmpname)) {$this->last_error = "Invalid post file method. File name is: ".$name;$this->halt($this->last_error);continue;}//移动文件后，重命名文件用。$basename = $this->getBaseName($name, ".".$type);//为防止文件名乱码$basename = iconv("UTF-8","gb2312", $basename);//移动后的文件名$saveas = $basename.time().".".$type;//组合新文件名再存到指定目录下，格式：存储路径 + 文件名 + 时间 + 扩展名$this->final_file_path = $this->save_file_path."/".$saveas;if(!move_uploaded_file($tmpname, $this->final_file_path)) {$this->last_error = $this->user_post_file['error'][$i];$this->halt($this->last_error);continue;}//存储当前文件的有关信息，以便其它程序调用。$this->save_info[] = array("name" => $name, "type" => $type,"mime_type" => $mime_type,"size" => $size, "saveas" => $saveas,"path" => $this->final_file_path);}}return count($this->save_info); //返回上传成功的文件数目}/*** 返回一些有用的信息，以便用于其它地方。*/function getSaveInfo() {return $this->save_info;}/*** 检测用户提交文件大小是否合法*/function checkSize($size) {if ($size > $this->max_file_size) {return false;}else {return true;}}/*** 检测用户提交文件类型是否合法*/function checkType($extension) {foreach ($this->allow_type as $type) {if (strcasecmp($extension , $type) == 0)return true;}return false;}/*** 显示出错信息*/function halt($msg) {printf("<b><UploadFile Error:></b> %s <br>\n", $msg);}/*** 取文件扩展名*/function getFileExt($filename) {$stuff = pathinfo($filename);return $stuff['extension'];}/*** 取给定文件文件名，不包括扩展名。*/function getBaseName($filename, $type) {$basename = basename($filename, $type);return $basename;}
}if (!empty($_POST['submit'])) {$upload = new UploadFile($_FILES['files'], './tmp');//上传用户文件，返回int值，为上传成功的文件个数。$num = $upload->upload();if ($num != 0) {echo "上传成功<br>";echo $num."个文件上传成功";}else {echo "上传失败<br>";}
}
?>
<form name="myForm" enctype="multipart/form-data" method="POST" action="">
<input type="file" name="files[]">
<input type="submit" name="submit" value="上传"><a href="#" οnclick="AddInput()">再上传一张</a>
</form>
</body>
</html>运行结果：
