php上传图片并压缩-thinkphp如何做图片压缩呢？

这里会使用到三个文件:

:连接数据库

test_:执行SQL语句

upload_:上传图片并压缩

三个文件代码如下:

连接数据库:

<?php

$db_host='';

$db_user='';

$db_psw='';

$db_name='';

$db_port='';

$sqlconn=new_ysqli($db_host,$db_user,$db_psw,$db_name);

$q="set_ames_tf8;";

$result=$sqlconn->query($q);

if(mysqli_connect_errno())_

_rintf("Connect_ailed:%s
",_ysqli_connect_error());

_xit();

}

?>

当然使用一些封装的数据库类也是可以的。

执行SQL语句:test_

<?php

require("");

require("upload_");

$real_img=$uploadfile;

$small_img=$uploadfile_resize;

$insert_sql="insert_nto_mg(real_img,small_img)_alues(?,?)";

$result=$sqlconn->_repare($insert_sql);

$result->_ind_param("ss",$real_img,$small_img);

$result->_xecute();

?>

上传图片并压缩:upload_

<?php

//设置文件保存目录

$uploaddir="upfiles/";

//设置允许上传文件的类型

$type=array("jpg","gif","bmp","jpeg","png");

//获取文件后缀名函数

function_ileext($filename)

{

_eturn_ubstr(strrchr($filename,'.'),1);

}

//生成随机文件名函数

function_andom($length)

{

$hash='CR-';

$chars='ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz';

$max=_trlen($chars)-1;

_t_srand((double)microtime()*1000000);

_or($i=0;$i<$length;$i++)

_

_$hash.=$chars[mt_rand(0,$max)];

_

_eturn$hash;

}

$a=strtolower(fileext($_FILES['filename']['name']));

//判断文件类型

if(!in_array(strtolower(fileext($_FILES['filename']['name'])),$type))

{

$text=implode(",",$type);

$ret_code=3;//文件类型错误

$page_result=$text;

$retArray=_rray('ret_code'=>$ret_code,'page_result'=>$page_result);

$retJson=_son_encode($retArray);

_cho$retJson;

_eturn;

}

//生成目标文件的文件名

else

{

$filename=explode(".",$_FILES['filename']['name']);

_o

_

_$filename[0]=random(10);//设置随机数长度

_$name=implode(".",$filename);

_//$name1=$name.".Mcncc";

_$uploadfile=$uploaddir.$name;

_

_hile(file_exists($uploadfile));

_f(move_uploaded_file($_FILES['filename']['tmp_name'],$uploadfile))

_

_if(is_uploaded_file($_FILES['filename']['tmp_name']))

_{

_$ret_code=1;//上传失败

_}

_lse

_//上传成功

_$ret_code=0;

_

_

$retArray=_rray('ret_code'=>$ret_code);

$retJson=_son_encode($retArray);

echo$retJson;

}

//压缩图片

$uploaddir_resize="upfiles_resize/";

$uploadfile_resize=$uploaddir_resize.$name;

//$pic_width_max=120;

//$pic_height_max=90;

//以上与下面段注释可以联合使用,可以使图片根据计算出来的比例压缩

$file_type=$_FILES["filename"]['type'];

function_esizeImage($uploadfile,$maxwidth,$maxheight,$name)

{

//取得当前图片大小

$width=_magesx($uploadfile);

$height=_magesy($uploadfile);

$i=0.5;

//生成缩略图的大小

_f(($width>$maxwidth)_|($height>$maxheight))

_

_/*

_$widthratio=$maxwidth/$width;

_$heightratio=$maxheight/$height;

_

_if($widthratio<$heightratio)

_{

_$ratio=$widthratio;

_}

_else

_{

__$ratio=$heightratio;

_}

_

_$newwidth=$width*$ratio;

_$newheight=$height*$ratio;

_*/

_$newwidth=$width*$i;

_$newheight=$height*$i;

_if(function_exists("imagecopyresampled"))

_{

_$uploaddir_resize=_magecreatetruecolor($newwidth,$newheight);

__magecopyresampled($uploaddir_resize,$uploadfile,0,0,0,0,$newwidth,$newheight,$width,$height);

_}

_else

_{

_$uploaddir_resize=_magecreate($newwidth,$newheight);

__magecopyresized($uploaddir_resize,$uploadfile,0,0,0,0,$newwidth,$newheight,$width,$height);

_}

_

_ImageJpeg($uploaddir_resize,$name);

_ImageDestroy($uploaddir_resize);

_

_lse

_

_ImageJpeg($uploadfile,$name);

_

}

if($_FILES["filename"]['size'])

{

_f($file_type=="image/pjpeg"||$file_type=="image/jpg"|$file_type=="image/jpeg")

_

_//$im=_magecreatefromjpeg($_FILES[$upload_input_name]['tmp_name']);

_$im=_magecreatefromjpeg($uploadfile);

_

_lseif($file_type=="image/x-png")

_

_//$im=_magecreatefrompng($_FILES[$upload_input_name]['tmp_name']);

_$im=_magecreatefromjpeg($uploadfile);

_

_lseif($file_type=="image/gif")

_

_//$im=_magecreatefromgif($_FILES[$upload_input_name]['tmp_name']);

_$im=_magecreatefromjpeg($uploadfile);

_

_lse//默认jpg

_

_$im=_magecreatefromjpeg($uploadfile);

_

_f($im)

_

_ResizeImage($im,$pic_width_max,$pic_height_max,$uploadfile_resize);

_

_ImageDestroy($im);

_

}

?>

请按照现实情况更改,test_中对应的信息。

望采纳,谢谢。