phpGD库生成缩略图的例子
                        
                            时间:2021-07-01 10:21:17
                            帮助过:29人阅读
							                        
                     
                    
                    
  - header("content-type:text/html;charset=gbk"); 
 - ini_set("date.timezone","Asia/chong"); 
 - //判断文件是否为空 
 - if(empty($_FILES)){ 
 - echo"上传文件过大"; 
 - exit; 
 - } 
 - //判断文件上传是否有错误 
 - if($_FILES['pic']['error']){ 
 - echo "上传文件"; 
 - exit; 
 - } 
 - //判断文件类型是否非法获取文件后缀 
 - $allowtype=array("jpg","png","jpeg","gif"); 
 - $a=explode('.',$_FILES['pic']['name']); 
 - $index=count($a)-1; 
 - $ex=strtolower($a[$index]); 
 - if(!in_array($ex,$allowtype)){ 
 - echo "上传文件非法"; 
 - exit; 
 - } 
 - $file=date('YmdHis').rand().".".$ex; 
 - $src=$_FILES['pic']['tmp_name']; 
 - $des="upload/".$file; 
 - $rs=move_uploaded_file($src,$des);
 //缩略图  - //读取已上传图片 
 - $image=imagecreatefromjpeg($des); 
 - $a=getimagesize($des); 
 - $w=$a[0]; 
 - $h=$a[1]; 
 - if($w>$h){ 
 - $width=300; 
 - $height=$width/$w*$h; 
 - }else if($w<$h){ 
 - $height=300; 
 - $width=$height/$h*$w; 
 - }else{ 
 - $width=300; 
 - $height=300; 
 - } 
 - //创建空白新图片 
 - $newimage=imagecreatetruecolor($width, $height); 
 - //copy源图片内容 copy新图片 
 - imagecopyresized($newimage, $image, 0,0, 0,0, $width, $height, $w, $h); 
 - $filename="upload/s_".$file; 
 - imagejpeg($newimage,$filename);
 
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