php图片上传并生成缩略图

在生成图片的缩略图，比如宽和高的比例时，可以自由修改。这个类可用于配合前段的iframe表单元素，生成无刷新的上传图片，并在前段指定区域立即显示的效果。其实还可以再加一个属性，把任何服务器错误都替换成一个更加友好的提示信息并返回给前段

<?php require_once "sql.tool.php";class Picture{//上传文件private $upfile;//保存后的源文件private $img;//上传文件的类型private $fileType;//上传图片保存的路径private $path;//上传图片的名字private $fname;//缩略图的宽度private $width;//缩略图的高度private $height;//错误信息private $noticeMsg=null;private $sql;public function __construct($upfile){$config = require "config.php";$this->width=$config['image']['width'];$this->height=$config['image']['height'];if(is_uploaded_file($upfile['tmp_name'])){$this->upfile = $upfile;}else{$this->noticeMsg = '非法文件';}$this->sql = new Sql();$this->moveFile();$this->zoomInPic();echo "<script> parent.document.getElementById('feedback').innerHTML='{$this->noticeMsg}'</script>";}private function checkFilesStatus(){//上传失败,分析原因if($this->upfile['error']>0){switch($this->upfile['error']){case 1://超过表单定义的MAX_FILE_SIZE$this->noticeMsg = '文件太大';break;case 2://超过系统定义,php.ini中设定的$this->noticeMsg = '文件太大';break;case 3:$this->noticeMsg = '文件不完整';break;case 4:$this->noticeMsg = '文件为空';break;}return 0;}else{//上传成功$this->noticeMsg = '上传成功';return 1;}}//检测上传文件类型private function checkFileType(){$fileType = strtolower(substr(strchr($this->upfile['name'],'.'),1));$this->fileType = $fileType;$defaultType=array('jpg', 'jpeg', 'png', 'gif');if(!in_array($fileType, $defaultType)) {$this->noticeMsg='文件类型不对';return 0;}return 1;}//保存上传文件private function moveFile(){if($this->checkFilesStatus() && $this->checkFileType()){$dirName = './upload/'.date("Ymd");if(!is_dir($dirName)){mkdir($dirName,0777, true);}$toFileName = $dirName."/".time().mt_rand(1,500).$this->upfile['name'];$this->path = $dirName;if(!move_uploaded_file($this->upfile['tmp_name'], $toFileName)) {die('移动文件失败');//系统错误}else{$this->img = $toFileName;}}}private function fileName(){$fname = basename($this->upfile['name'], strchr($this->upfile['name'], '.'));$this->fname = time().mt_rand(1,500).$fname.'small';}//生成图片缩略图private function zoomInPic(){$src;$this->fileName();switch($this->fileType){case 'jpg':case 'jpeg':$src = imagecreatefromjpeg($this->img);break;case 'gif':$src = imagecreatefromgif($this->img);break;case 'png':$src = imagecreatefrompng($this->img);break;}//获取上传图片的宽和高$src_w = imagesx($src);$src_h = imagesy($src);//生成缩略图//在属性里定义缩略图的宽和高，并将原图按照比例缩放//缩放算法是: 新宽/原宽 = 新高/原高,这样就能等比例缩放了...../* if($src_w > $src_h){$new_w = $this->width;$new_h = ceil(($this->width/$src_w)*$src_h);}else{$new_h = $this->height;$new_w = ceil(($this->height/$src_h)*$src_w);} */$new_h = $this->height;$new_w = ceil(($this->height/$src_h)*$src_w);$paint = imagecreatetruecolor($new_w, $new_h);imagecopyresampled($paint, $src, 0,0,0,0, $new_w, $new_h, $src_w, $src_h);//在原图上保存缩略图switch($this->fileType){case 'jpg':case 'jpeg':$src = imagejpeg($paint, $this->path.'/'.$this->fname.'.'.$this->fileType);break;case 'gif':$src = imagegif($paint, $this->path.'/'.$this->fname.'.'.$this->fileType);break;case 'png':$src = imagepng($paint, $this->path.'/'.$this->fname.'.'.$this->fileType);break;}//释放资源imagedestroy($paint);sleep(2);unlink($this->img);//因为返回的是img链接资源，所以可以省略HEADER头部$this->noticeMsg="<img src=".$this->path.'/'.$this->fname.'.'.$this->fileType.">";$sources = $this->path.'/'.$this->fname.'.'.$this->fileType;$this->sql->setImage("$sources");}}?>