PHP常用的类封装小结

本文实例讲述了PHP常用的类封装。分享给大家供大家参考，具体如下：

这4个类分别是Mysql类、 分页类、缩略图类、上传类。

Mysql类

query($sql);
  }
  
  public static function getAll($sql){
    $data = array();
    $res = self::query($sql);
    while($row = $res->fetch_assoc()){
      $data[] = $row;
    }
    return $data;
  }
  
  public static function getRow($row){
    $res = self::query($sql);
    return $res->fetch_assoc();
  }
  
  public static function getOne($sql){
    $res = self::query($sql);
    $data = $res->fetch_row();
    return $data[0];
  }
  
  public static function exec($table,$data,$act='insert',$where='0'){
    //插入操作
    if($act == 'insert'){
      $sql = 'insert into '.$table;
      $sql .= ' ('.implode(',',array_keys($data)).')';
      $sql .= " values ('".implode("','",array_values($data))."')";
    }else if($act == 'update'){
      $sql = 'update '.$table.' set ';
      foreach ($data as $k => $v) {
 $sql .= $k.'='."'$v',";
      }
      $sql = rtrim($sql,',');
      $sql .= ' where 1 and '.$where;
    }
    return self::query($sql);
  }
  
  public static function getLastId(){
    return self::conn()->insert_id;
  }
  
  public static function getAffectedRows(){
    return self::conn()->affected_rows;
  }
  
  public static function close(){
    return self::conn()->close();
  }
}
?>

分页类

num = $num;
    $this->cnt = $cnt;
    $this->curr = empty($_GET[$this->p]) ? 1 : intval($_GET[$this->p]);
    $this->curr = $this->curr > 0 ? $this->curr : 1;
    $this->firstRow  = $this->cnt * ($this->curr - 1);
    $this->getPage();
  }
  
  private function getPage(){
    $page = ceil($this->num / $this->cnt);//总的页数
    $left = max(1,$this->curr - floor($this->pageCnt/2));//计算最左边页码
    $right = min($left + $this->pageCnt - 1 ,$page);//计算最右边页码
    $left = max(1,$right - ($this->pageCnt - 1));//当前页码往右靠，需要重新计算左边页面的值
    for($i=$left;$i<=$right;$i++){
      if($i == 1){
 $index = '第1页';
      }else if($i == $page){
 $index = '最后一页';
      }else{
 $index = '第'.$i.'页';
      }
      $_GET['page'] = $i;
      $this->pageIndex[$index] = http_build_query($_GET);
    }
  }
  
  public function show(){
    return $this->pageIndex;
  }
}
?>

缩略图类

sourcePath = $sourcePath;
    //获取缩略图的大小
    $this->thumbWidth = $thumbWidth;
    $this->thumbHeight = $thumbHeight;
    $this->thumbPath = $this->getThumbPath();
    //计算大图的大小
    list($this->sourceWidth,$this->sourceHeight,$this->sourceType) = getimagesize($this->sourcePath);
  }
  
  private function getThumbPath(){
    $ext = $this->getExt();
    $filename = basename($this->sourcePath,'.'.$ext).'_thumb'.'.'.$ext;
    return $thumbPath = __DIR__.'/'.$filename;
  }
  
  private function getExt(){
    return pathinfo($this->sourcePath,PATHINFO_EXTENSION);
  }
  
  public function getType(){
    $typeArr = array(
      1 => 'gif',
      2 => 'jpeg',
      3 => 'png',
      15 => 'wbmp'
    );
    if(!in_array($this->sourceType, array_keys($typeArr))){
      return false;
    }
    return $typeArr[$this->sourceType];
  }
  
  public function calculateRate(){
    return min($this->thumbWidth / $this->sourceWidth,$this->thumbHeight / $this->sourceHeight);
  }
  
  public function getImageSizeByRate($rate){
    $width = $this->sourceWidth * $rate;
    $height = $this->sourceHeight * $rate;
    return array('w'=>$width,'h'=>$height);
  }
  
  public function saveFile($image){
    $method = "image".$this->getType();
    $method($image,$this->thumbPath);
  }
  
  public function draw(){
    if(!($type = $this->getType())){
      echo "文件类型不支持";
      return ;
    }
    //创建大图和小图的画布
    $method = "imagecreatefrom".$type;
    $bigCanvas = $method($this->sourcePath);
    $smallCanvas = imagecreatetruecolor($this->thumbWidth, $this->thumbHeight);
    //创建白色画笔，并给小图画布填充背景
    $white = imagecolorallocate($smallCanvas, 255, 255, 255);
    imagefill($smallCanvas, 0, 0, $white);
    //计算大图的缩放比例
    $rate = $this->calculateRate();
    //计算大图缩放后的大小信息
    $info = $this->getImageSizeByRate($rate);
    //进行缩放
    imagecopyresampled($smallCanvas, $bigCanvas,
      ($this->thumbWidth - $info['w']) / 2 , ($this->thumbHeight - $info['h']) / 2,
      0, 0, $info['w'], $info['h'], $this->sourceWidth, $this->sourceHeight);
    //保存成文件
    $this->saveFile($smallCanvas);
    //销毁画布
    imagedestroy($bigCanvas);
    imagedestroy($smallCanvas);
  }
}
?>

上传类

getExt($filename);
    return in_array($ext,$this->allowExt);
  }
  
  public function checkSize($size){
    return $size < $this->maxSize * 1024 * 1024;
  }
  
  public function randName($len=6){
    return substr(str_shuffle('abcdefghjkmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ234565789'),0,$len);
  }
  
  public function createDir(){
    $dir = './upload/'.date('Y/m/d',time());
    if(is_dir($dir) || mkdir($dir,0777,true)){
      return $dir;
    }
  }
  
  public function uploadFile($flag){
    if($_FILES[$flag]['name'] === '' || $_FILES[$flag]['error'] !== 0){
      echo "没有上传文件";
      return;
    }
    $info = $this->getInfo($flag);
    if(!$this->checkExt($info['name'])){
      echo "不支持的文件类型";
      return;
    }
    if(!$this->checkSize($info['size'])){
      echo "文件大小超过限制";
      return;
    }
    $filename = $this->randName().'.'.$this->getExt($info['name']);
    $dir = $this->createDir();
    if(!move_uploaded_file($info['tmp_name'], $dir.'/'.$filename)){
      echo "文件上传失败";
    }else{
      return array('filename'=>$filename,'dir'=>$dir);
    }
  }
}
?>

更多关于PHP相关内容感兴趣的读者可查看本站专题：《php+mysql数据库操作入门教程》、《php+mysqli数据库程序设计技巧总结》、《php面向对象程序设计入门教程》、《PHP数组(Array)操作技巧大全》、《php字符串(string)用法总结》、《PHP网络编程技巧总结》及《php常见数据库操作技巧汇总》

希望本文所述对大家PHP程序设计有所帮助。