下面通过一段代码给大家演示下，主要分为1.前台文件index.html和 2.后台文件upload.php。具体代码如下所示：

1.前台文件index.html
 















 
SWFUpload
 v2.2.0

 
 

Hanization By Leo.C,

2.后台文件upload.php

  $multiplier*(int)$POST_MAX_SIZE && $POST_MAX_SIZE) {
  header("HTTP/1.1 500 Internal Server Error");
  echo "POST exceeded maximum allowed size.";
  exit(0);
 }
 // 基本设置
 $save_path = getcwd() . "/file/";    　　　　　　　　　　　　// 文件上传位置
 $upload_name = "Filedata";
 $max_file_size_in_bytes = 2147483647;    　　　　　　　　　// 2GB
 $extension_whitelist = array("doc", "txt", "jpg", "gif", "png"); // 允许文件类型
 $valid_chars_regex = '.A-Z0-9_ !@#$%^&()+={}[]',~`-';   // 文件名规则
 // 其他变量
 $MAX_FILENAME_LENGTH = 260;
 $file_name = "";
 $file_extension = "";
 $uploadErrors = array(
  0=>"文件上传成功",
  1=>"上传的文件超过了 php.ini 文件中的 upload_max_filesize directive 里的设置",
  2=>"上传的文件超过了 HTML form 文件中的 MAX_FILE_SIZE directive 里的设置",
  3=>"上传的文件仅为部分文件",
  4=>"没有文件上传",
  6=>"缺少临时文件夹"
 );
 // 检测文件是否上传正确
 if (!isset($_FILES[$upload_name])) {
  HandleError("No upload found in $_FILES for " . $upload_name);
  exit(0);
 } else if (isset($_FILES[$upload_name]["error"]) && $_FILES[$upload_name]["error"] != 0) {
  HandleError($uploadErrors[$_FILES[$upload_name]["error"]]);
  exit(0);
 } else if (!isset($_FILES[$upload_name]["tmp_name"]) || !@is_uploaded_file($_FILES[$upload_name]["tmp_name"])) {
  HandleError("Upload failed is_uploaded_file test.");
  exit(0);
 } else if (!isset($_FILES[$upload_name]['name'])) {
  HandleError("File has no name.");
  exit(0);
 }
 // 检测文件尺寸
 $file_size = @filesize($_FILES[$upload_name]["tmp_name"]);
 if (!$file_size || $file_size > $max_file_size_in_bytes) {
  HandleError("File exceeds the maximum allowed size");
  exit(0);
 }
  if ($file_size <= 0) {
  HandleError("File size outside allowed lower bound");
  exit(0);
 }
 // 检测文件名字为空
 $file_name = preg_replace('/[^'.$valid_chars_regex.']|.+$/i', "", basename($_FILES[$upload_name]['name']));
 if (strlen($file_name) == 0 || strlen($file_name) > $MAX_FILENAME_LENGTH) {
  HandleError("Invalid file name");
  exit(0);
 }
 // 检测重名文件
 if (file_exists($save_path . $file_name)) {
  HandleError("File with this name already exists");
  exit(0);
 }
 // 检测后缀名
 $path_info = pathinfo($_FILES[$upload_name]['name']);
 $file_extension = $path_info["extension"];
 $is_valid_extension = false;
 foreach ($extension_whitelist as $extension) {
  if (strcasecmp($file_extension, $extension) == 0) {
   $is_valid_extension = true;
   break;
  }
 }
 if (!$is_valid_extension) {
  HandleError("Invalid file extension");
  exit(0);
 }
 // 保存文件
 if (!@move_uploaded_file($_FILES[$upload_name]["tmp_name"], $save_path.$file_name)) {
  HandleError("文件无法保存.");
  exit(0);
 }
 // 成功输出
  echo "File Received";
 exit(0);
 function HandleError($message) {
 header("HTTP/1.1 500 Internal Server Error");
 echo $message;
}
?>

以上代码就是实现文件上传之SwFUpload插件的全部内容，希望大家喜欢。