PHP image file upload class (can automatically generate thumbnails)

<?php
/**
功 能：文件上传类 支持文件夹自动分组保存;
创建类：参数(文件域,文件原名,文件大小);
$myupload = new upfileClass($upfile,$upfile_name,$upfile_size);
$myupload->savefile(); # 保存方法 并返回保存路径附带文件名;

@ echo MakeBuild($BuildFile,$newFile,$File_width);
生成指定文件的缩略图;
$myupload->MakeBuild("images/a.jpg","news/b.jpg","100");
*/

class upfileClass
{
var $upfile, $upfile_name, $upfile_size;

var $new_upfile_name;   # 上传后的文件名称 ; 
var $fleth, $fileExtent; # 文件扩展名(类型) ; 
var $f1, $f2, $f3;   # 文件保存路径(多级) upfiles/2008-01/08/;
var $filename;    # 文件(带路径) ;

var $maxSize, $File_type; # 允许上传文件的大小 允许上传文件的类型 ;

var $BuildFile,$newFile,$File_width,$File_height,$rate;

function upfileClass($upfile,$upfile_name,$upfile_size)
{
   $this->upfile = $upfile;
  $this->upfile_name = $upfile_name;
  $this->upfile_size = $upfile_size;
  
  $this->new_upfile_name = $this->CreateNewFilename($this->upfile_name);
  
  $this->f1 = "upfiles";
  $this->f2 = $this->f1."/".date('Y')."-".date('m');
$this->f3 = $this->f2."/".date('d');
  
  $this->filename = $this->f3 . "/" . $this->new_upfile_name;
  $this->maxSize = 500*1024;    # 文件大小 500KB
  $this->File_type = "gif/jpg/jpeg/png"; # 允许上传的文件类型
}

# 创建新文件名 (原文件名)
function CreateNewFilename($file_name)
{
   $this->fleth = explode(".",$file_name);
   $this->fileExtent = $this->fleth[(int)count($this->fleth)-1]; # 获取文件后缀;
   $tmpstr = date('YmdHis') . "." .$this->fileExtent;    # 创建新文件名;
   return $tmpstr;
}

# 检测文件类型是否正确
function chk_fileExtent()
{
   $iwTrue = 0;
   $fle = explode("/",$this->File_type);
   for($i=0; $i < count($fle); $i++){
    if( $this->fileExtent == $fle[$i] )
    {
     $iwTrue = (int) $iwTrue + 1;
    }
   }
   if( $iwTrue == 0 ){
    $this->msg("文件不符合 ".$this->File_type." 格式!");
   }
}

# 提示错误信息并终止操作
function msg($Error)
{
   echo "<script language=/"javascript/">/n";
   echo " alert('".$Error."');/n";
   echo " window.history.back();/n";
   echo "</script>/n";
   die();
}

# 保存文件
function savefile()
{
   $this->chk_fileExtent();
   $this->chk_fileSize();
   $this->CreateFolder( "../".$this->f1 );
   $this->CreateFolder( "../".$this->f2 );
   $this->CreateFolder( "../".$this->f3 );
   return $this->chk_savefile();
}

# 检测上传结果是否成功
function chk_savefile()
{
   $copymsg = copy($this->upfile,"../".$this->filename);
   if( $copymsg ){
    return $this->filename;
   }
   else{
    $this->msg("文件上传失败! /n/n请重新上传! ");
   }
}

# 创建文件夹
function CreateFolder($foldername)
{
   if( !is_dir($foldername) ){
    mkdir($foldername,0777);
   }
}

# 检测文件大小
function chk_fileSize()
{
   if( $this->upfile_size > $this->maxSize ){
    $this->msg("目标文件不能大于". $this->maxSize/1024 ." KB");
   }
}

# 删除文件($filePath 文件相对路径)
function Deletefile($filePath)
{
   if( !is_file($filePath) ){
    return false;
   }
   else{
    $ending = @unlink($filePath);
    return $ending;
   }
}

/*
   函数：生成缩略图
    MakeBuild("images/a.jpg","news/b.jpg","100");
   参数：
   echo $BuildFile;   原图 带路径
   echo $newFile;    生成的缩略图 带路径
   echo $File_width;   缩略图宽度值
   echo $File_height;   缩略图高度值 (默认为宽度的比例值)
   echo $rate;     缩略图象品质;
*/
function MakeBuild($BuildFile,$newFile,$File_width,$File_height=0,$rate=100) 
{ 
   if(!is_file($BuildFile)){
    $this->msg("文件 ".$BuildFile." 不是一个有效的图形文件！/n/n系统无法生成该文件的缩略图！");
    return false;
   }
   $data = GetImageSize($BuildFile); 
   switch($data[2]){ 
   case 1: 
    $im = @ImageCreateFromGIF($BuildFile); 
    break;
   case 2: 
    $im = @ImageCreateFromJPEG($BuildFile); 
    break;
   case 3: 
    $im = @ImageCreateFromPNG($BuildFile); 
    break;
   } 
   if(!$im){
    return false;
   }
   else{
    $srcW=ImageSX($im);  # 取得原图宽度;
    $srcH=ImageSY($im); # 取得原图高度;
    $dstX=0; 
    $dstY=0; 
   
    if($File_height==0){
     $File_height = $File_width/$srcW*$srcH;
    }
   
    if ($srcW*$File_height>$srcH*$File_width){ 
     $fFile_height = round($srcH*$File_width/$srcW); 
     $dstY = floor(($File_height-$fFile_height)/2); 
     $fFile_width = $File_width; 
    } 
    else { 
     $fFile_width = round($srcW*$File_height/$srcH); 
     $dstX = floor(($File_width-$fFile_width)/2); 
     $fFile_height = $File_height; 
    } 
    $ni = ImageCreateTrueColor($File_width,$File_height); 
    $dstX = ($dstX<0)?0:$dstX; 
    $dstY = ($dstX<0)?0:$dstY; 
    $dstX = ($dstX>($File_width/2))?floor($File_width/2):$dstX; 
    $dstY = ($dstY>($File_height/2))?floor($File_height/s):$dstY; 
    ImageCopyResized($ni,$im,$dstX,$dstY,0,0,$fFile_width,$fFile_height,$srcW,$srcH); 
   
    ImageJpeg($ni,$newFile,$rate); # 生成缩略图;
    imagedestroy($im);     # imagedestroy(resource) 释放image关联的内存
   }
} 

}
?>