php下载图片到本地，图片打不开
环境：wampserveer
数据库编码：统一utf8_general_ci
php文件编码:utf-8
该函数不与数据库连接时,下载正常
我用php上传统一图片后再下载就无法打开
我怀疑是上传到mysql后文件编码问题,但从未涉及这一方面,小弟特此求教如何解决
function dl_file($file){ //这是下载文件的函数,$file是文件路径. //First, see if the file exists if (!is_file($file)) { die("<b>404 File not found!</b>"); } //Gather relevent info about file $len = filesize($file); $filename = basename($file); $file_extension = strtolower(substr(strrchr($filename,"."),1)); //This will set the Content-Type to the appropriate setting for the file switch( $file_extension ) { case "pdf": $ctype="application/pdf"; break; case "exe": $ctype="application/octet-stream"; break; case "zip": $ctype="application/zip"; break; case "doc": $ctype="application/msword"; break; case "xls": $ctype="application/vnd.ms-excel"; break; case "ppt": $ctype="application/vnd.ms-powerpoint"; break; case "gif": $ctype="image/gif"; break; case "png": $ctype="image/png"; break; case "jpeg": case "jpg": $ctype="image/jpg"; break; case "mp3": $ctype="audio/mpeg"; break; case "wav": $ctype="audio/x-wav"; break; case "mpeg": case "mpg": case "mpe": $ctype="video/mpeg"; break; case "mov": $ctype="video/quicktime"; break; case "avi": $ctype="video/x-msvideo"; break; //The following are for extensions that shouldn't be downloaded (sensitive stuff, like php files) case "php": case "htm": case "html": case "txt": die("<b>Cannot be used for ". $file_extension ." files!</b>"); break; default: $ctype="application/force-download"; } //Begin writing headers header("Pragma: public"); header("Expires: 0"); header("Cache-Control: must-rev alidate, post-check=0, pre-check=0"); header("Cache-Control: public"); header("Content-Description: File Transfer"); //Use the switch-generated Content-Type header("Content-Type: $ctype"); //Force the download $header="Content-Disposition: attachment; filename=".$filename.";"; header($header); header("Content-Transfer-Encoding: binary"); header("Content-Length: ".$len); @readfile($file); exit;}