有缩略图功能 但是 感觉不全面，而且有点问题，继续学习，将来以后修改下

<form action="<?php $_SERVER['PHP_SELF']; ?>" enctype="multipart/form-data" method="post" ><input type="text" name="name" /><input type="file" name="file" /><input type="submit" name='submit' value="提交" ></form> 
 
<?php 
/** 
 * Created by PhpStorm. 
 * User: Administrator 
 * Date: 2016/6/28 
 * Time: 21:04 
 */
 
class upload{ 
   protected $fileMine;//文件上传类型 
   protected $filepath;//文件上传路径 
   protected $filemax;//文件上传大小 
   protected $fileExt;//文件上传格式 
   protected $filename;//文件名 
   protected $fileerror;//文件出错设置 
   protected $fileflag;//文件检测 
   protected $fileinfo; //FILES 
   protected $ext; //文件扩展 
   protected $path; 
 
  //文件上传 
  public function __construct($filename="file",$filemax=20000000,$filepath="./Uploads",$fileflag=true,$fileExt=array('jpg','exe'),$fileMine=array('image/jpeg')) 
  { 
    $this->filename=$filename; 
    $this->fileinfo=$_FILES[$this->filename]; 
    $this->filemax=$filemax; 
    $this->filepath=$filepath; 
    $this->fileflag=$fileflag; 
    $this->fileExt=$fileExt; 
    $this->fileMine=$fileMine; 
 
    //var_dump($this->filename); 
 
  } 
 
  //错误判断 
  public function UpError(){ 
 
      if($this->fileinfo['error']>0){ 
        switch($this->fileinfo['error']) 
        { 
          case 1: 
          $this->fileerror="上传文件大小超过服务器允许上传的最大值，php.ini中设置upload_max_filesize选项限制的值 "; 
            break; 
          case 2: 
            $this->fileerror="上传文件大小超过HTML表单中隐藏域MAX_FILE_SIZE选项指定的值"; 
            break; 
          case 3: 
            $this->fileerror="文件部分被上传"; 
            break; 
          case 4: 
            $this->fileerror="没有选择上传文件"; 
            break; 
          case 5: 
            $this->fileerror="未找到临时目录"; 
            break; 
          case 6: 
            $this->fileerror="文件写入失败"; 
            break; 
          case 7: 
            $this->fileerror="php文件上传扩展没有打开 "; 
            break; 
          case 8: 
            $this->fileerror=""; 
            break; 
 
        } 
        return false; 
      } 
      return true; 
 
  } 
 
  //检测文件类型 
  public function UpMine(){ 
    if(!in_array($this->fileinfo['type'],$this->fileMine)) { 
      $this->error="文件上传类型不对"; 
      return false; 
    } 
    return true; 
 
  } 
  //检测文件格式 
  public function UpExt(){ 
    $this->ext=pathinfo($this->fileinfo['name'],PATHINFO_EXTENSION); 
    //var_dump($ext); 
    if(!in_array($this->ext,$this->fileExt)){ 
      $this->fileerror="文件格式不对"; 
      return false; 
    } 
    return true; 
  } 
  //检测文件路径 
  public function UpPath(){ 
    if(!file_exists($this->filepath)){ 
      mkdir($this->filepath,0777,true); 
    } 
  } 
  //检测文件大小 
  public function UpSize(){ 
    $max=$this->fileinfo['size']; 
    if($max>$this->filemax){ 
      $this->fileerror="文件过大"; 
      return false; 
    } 
    return true; 
  } 
  //检测文件是否HTTP 
  public function UpPost(){ 
    if(!is_uploaded_file($this->fileinfo['tmp_name'])){ 
      $this->fileerror="恶意上偿还"; 
      return false; 
    } 
    return true; 
  } 
  //文件名防止重复 
  public function Upname(){ 
    return md5(uniqid(microtime(true),true)); 
  } 
 
  //图片缩略图 
  public function Smallimg($x=100,$y=100){ 
    $imgAtt=getimagesize($this->path); 
    //图像宽，高，类型 
    $imgWidth=$imgAtt[0]; 
    $imgHeight=$imgAtt[1]; 
    $imgext=$imgAtt[2]; 
    //等比列缩放 
 
    if(($x/$imgWidth)>($y/$imgHeight)){ 
      $bl=$y/$imgHeight; 
    }else{ 
      $bl=$x/$imgWidth; 
    } 
    $x=floor($imgWidth*$bl); //缩放后 
    $y=floor($imgHeight*$bl); 
    $images=imagecreatetruecolor($x,$y); 
    $big=imagecreatefromjpeg($this->path); 
    imagecopyresized($images,$big,0,0,0,0,$x,$y,$imgWidth,$imgWidth); 
    switch($imgext){ 
      case 1: 
        $imageout=imagecreatefromgif($this->path); 
        break; 
      case 2: 
        $imageout=imagecreatefromjpeg($this->path); 
        break; 
      case 3: 
        $imageout=imagecreatefromgif($this->path); 
        break; 
    } 
    $im=imagejpeg($images,$this->path); 
 
 
 
 
  } 
 
  //文件双传 
  public function uploads() 
  { 
    if($this->UpError()&&$this->UpMine()&&$this->UpExt()&&$this->UpSize()&&$this->UpPost()){ 
      $this->UpPath(); 
      $names=$this->Upname(); 
      $this->path=$this->filepath.'/'. $names.'.'.$this->ext; 
 
      if(move_uploaded_file($this->fileinfo['tmp_name'], $this->path)){ 
        return $this->path; 
      }else{ 
        $this->fileerror="上传失败"; 
      } 
    }else{ 
      exit("<b>".$this->fileerror."</b>"); 
    } 
  } 
 
 
} 
 
 
?>

<?php 
  header("content-type:imagejpeg"); 
header("Content-type:text/html;charset=utf-8"); 
 require 'list.php'; 
 $u=new upload(); 
 $a=$u->uploads(); 
 
 $c=$u->Smallimg(); 
echo "<img src={$a} />"; 
echo "<img src={$c} />"; 
 
?> 

<!DOCTYPE html> 
<html> 
<head> 
<meta charset="utf-8"> 
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> 
<title>Examples</title> 
<meta name="description" content=""> 
<meta name="keywords" content=""> 
<link href="http://www.gimoo.net/t/1812/5c02567abb925.html" rel="stylesheet"> 
</head> 
<body> 
  <form action="ce.php" enctype="multipart/form-data" method="post" > 
  <input type="text" name="name" /><input type="file" name="file" /> 
  <input type="submit" name='submit' value="提交" > 
  </form> 
</body> 
</html>

以上这篇PHP之图片上传类实例代码(加了缩略图)就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持绿夏网。