PHP generates verification code images from entry and proficiency tutorials_PHP tutorial

It is quite simple to generate verification code images in php, because php provides us with the graphics gd.dll library. To enable the gd graphics library, we only need to put php-gd in front of php.ini ; Just go.

Method 1

The code is as follows

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代码如下	复制代码
$authnum=''; $ychar="0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z"; $list=explode(",",$ychar);//分割函数 for($i=0;$i<4;$i++){ $randnum=rand(0,35); $authnum.=$list[$randnum];//以数组的形式输出

$authnum='';

$ychar="0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M, N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
$list=explode(",",$ychar);//Split function

for($i=0;$i<4;$i++){

代码如下	复制代码
private function createCheckCode() { for(i=0;icodeNum;i++) { number = rand(0,2); switch(number) { case 0: rand_number = rand(48,57); break;//数字 case 1: rand_number = rand(65,90);break;//大写字母 case 2: rand_number = rand(97,122);break;//小写字母 } $asc = sprintf("%c",rand_number); $asc_number = asc_number.asc; } return asc_number; }

$randnum=rand(0,35);

$authnum.=$list[$randnum];//Output in the form of array

Method 2:

代码如下	复制代码
srand(microtime()*100000);//相当于计时器 $string="abcdefghigklmnopqrstuvwxyz123456789"; for($i=0;$i<4;$i++) { $new_number.=$string[rand(0,strlen($string)-1)];//随即的产生一个数组 }

The code is as follows

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private function createCheckCode()
{

for(i=0;icodeNum;i++)

代码如下	复制代码
for($i=0;$i<4;$i++) { $rand.=dechex(rand(1,15));//将十进制转化为十六进制 }

{

number = rand(0,2);

switch(number)

{

case 0: rand_number = rand(48,57); break;//Number

代码如下

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//che.php session_start(); for($i=0;$i<4;$i++) { $rand.=dechex(rand(1,15)); } $_SESSION['check_num']=$rand; $image=imagecreatetruecolor(50,30); $bg=imagecolorallocate($im,0,0,0);//第一次用调色板的时候，背景颜色 $te=imagecolorallocate($im,255,255,255); imagestring($image,6,rand(0,20),rand(0,2),$rand,$te); ob_clean();//PHP网页中因为 要生成验证码而出现 图像"http://localhost/**.php"因其本身有错无法显示 header("Content-type:image/jpeg"); imagejpeg($image); ?>

case 1: rand_number = rand(65,90);break;//uppercase letters case 2: rand_number = rand(97,122);break;//lowercase letters } $asc = sprintf("%c",rand_number); $asc_number = asc_number.asc; } return asc_number; }

Method 3:

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srand(microtime()*100000);/ /equivalent to timer $string="abcdefghigklmnopqrstuvwxyz123456789"; for($i=0;$i<4;$i++) <🎜> { <🎜> $new_number.=$string[rand(0,strlen($string)-1)];//Suddenly generate an array <🎜> }

<🎜>Method 4: <🎜> <🎜>

The code is as follows	Copy code
<🎜>for($i=0;$i<4;$i++) <🎜> { <🎜> $rand.=dechex(rand(1,15));//Convert decimal to hexadecimal <🎜> }<🎜> <🎜><🎜> <🎜>

<🎜>Randomly generate numbers and letter codes: <🎜> <🎜> <🎜>

The code is as follows

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//che.php <🎜> session_start(); <🎜> for($i=0;$i<4;$i++) <🎜> { <🎜> $rand.=dechex(rand(1,15)); <🎜> } <🎜> $_SESSION['check_num']=$rand; <🎜> $image=imagecreatetruecolor(50,30); <🎜> $bg=imagecolorallocate($im,0,0,0);//The first time you use the palette, the background color <🎜> $te=imagecolorallocate($im,255,255,255); <🎜> imagestring($image,6,rand(0,20),rand(0,2),$rand,$te); <🎜> ob_clean();//The image "http://localhost/**.php" appears in the PHP web page because it needs to generate a verification code because it has errors and cannot be displayed <🎜> header("Content-type:image/jpeg"); imagejpeg($image); <🎜> ?>

Code to draw interference lines on pictures:

The code is as follows

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for($i=0;$i< 8;$i++)//Draw multiple lines

代码如下	复制代码
for($i=0;$i<8;$i++)//画出多条线 { $cg=imagecolorallocate($im,rand(0,255),rand(0,255),rand(0,255));//产生随机的颜色 imageline($im,rand(10,40),0,rand(10,40),20,$cg); }

{

$cg=imagecolorallocate($im,rand(0,255),rand(0,255),rand(0,255));//Generate random colors
imageline($im,rand(10,40),0,rand(10,40),20,$cg);

}

代码如下	复制代码
for($i=0;$i<80;$i++)//画出多个点 { imagesetpixel($im,rand(0,40),rand(0,20),$cg); }

Code to draw interference points on pictures:

The code is as follows

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for($i=0;$i< 80;$i++)//Draw multiple points

{

代码如下	复制代码
$str=array('我','我','亲','亲');//存储显示的汉字 for($i=0;$i<4;$i++) { $sss.=$str[rand(0,3)];//随机显示汉字 } //$str=iconv("gb2312","utf-8",$str); //汉字编码转化，我的好像不需要 imagettftext($im,10,0,rand(5,60),rand(5,60),$te,"simhei.ttf",$sss);//

imagesetpixel($im,rand(0,40),rand(0,20),$cg); <🎜> }

<🎜>Write text into image code: <🎜> <🎜>

The code is as follows	Copy code
<🎜>$str=array('I','I','Dear','Dear');//Storage the displayed Chinese characters <🎜> for($i=0;$i<4;$i++) <🎜> { <🎜> $sss.=$str[rand(0,3)];//Display Chinese characters randomly <🎜> }<🎜> <🎜>//$str=iconv("gb2312","utf-8",$str); //Chinese character encoding conversion, mine doesn’t seem to need it <🎜> imagettftext($im,10,0,rand(5,60),rand(5,60),$te,"simhei.ttf",$sss);//<🎜>

Finally, we share a complete example based on actual practice

代码如下

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/** * 生成验证码图片 * * @param String $word 验证码在session中的变量名称 */ function valiCode($word='randcode'){ Header("Content-type: image/gif"); $border = 0; //是否要边框 1要:0不要 $how = 4; //验证码位数 $w = $how*15; //图片宽度 $h = 18; //图片高度 $fontsize = 10; //字体大小 $alpha = "abcdefghijkmnpqrstuvwxyz"; //验证码内容1:字母 $number = "23456789"; //验证码内容2:数字 $randcode = ""; //验证码字符串初始化 srand((double)microtime()*1000000); //初始化随机数种子 $im = ImageCreate($w, $h); //创建验证图片 /* * 绘制基本框架 */ $bgcolor = ImageColorAllocate($im, 255, 255, 255); //设置背景颜色 ImageFill($im, 0, 0, $bgcolor); //填充背景色 if($border) { $black = ImageColorAllocate($im, 0, 0, 0); //设置边框颜色 ImageRectangle($im, 0, 0, $w-1, $h-1, $black);//绘制边框 } /* * 逐位产生随机字符 */ for($i=0; $i<$how; $i++) { $alpha_or_number = mt_rand(0, 1); //字母还是数字 $str = $alpha_or_number ? $alpha : $number; $which = mt_rand(0, strlen($str)-1); //取哪个字符 $code = substr($str, $which, 1); //取字符 $j = !$i ? 4 : $j+15; //绘字符位置 $color3 = ImageColorAllocate($im, mt_rand(0,100), mt_rand(0,100), mt_rand(0,100)); //字符随即颜色 ImageChar($im, $fontsize, $j, 3, $code, $color3); //绘字符 $randcode .= $code; //逐位加入验证码字符串 } /* * 如果需要添加干扰就将注释去掉 * * 以下for()循环为绘背景干扰线代码 */ /* + -------------------------------绘背景干扰线 开始-------------------------------------------- + */ for($i=0; $i<5; $i++)//绘背景干扰线 { $color1 = ImageColorAllocate($im, mt_rand(0,255), mt_rand(0,255), mt_rand(0,255)); //干扰线颜色 ImageArc($im, mt_rand(-5,$w), mt_rand(-5,$h), mt_rand(20,300), mt_rand(20,200), 55, 44, $color1); //干扰线 } /* + -------------------------------绘背景干扰线 结束-------------------------------------- + */ /* * 如果需要添加干扰就将注释去掉 * * 以下for()循环为绘背景干扰点代码 */ /* + --------------------------------绘背景干扰点 开始------------------------------------------ + */ for($i=0; $i<$how*40; $i++)//绘背景干扰点 { $color2 = ImageColorAllocate($im, mt_rand(0,255), mt_rand(0,255), mt_rand(0,255)); //干扰点颜色 ImageSetPixel($im, mt_rand(0,$w), mt_rand(0,$h), $color2); //干扰点 } /* + --------------------------------绘背景干扰点 结束------------------------------------------ + */ //把验证码字符串写入session 方便提交登录信息时检验验证码是否正确 例如：$_POST['randcode'] = $_SESSION['randcode'] $_SESSION[$word] = $randcode; /*绘图结束*/ Imagegif($im); ImageDestroy($im); /*绘图结束*/ }

The calling method is also very simple. Save the above example in the img.php file, and then go to the page you want to call
The html page is as follows

Verification code:

Can’t see clearly? Change This will enable you to call the verification code. Add another submission to verify whether the verification code is correct

The code is as follows

代码如下	复制代码
验证码：       看不清？换一个

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The code is as follows

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session_start(); if((strtoupper($_POST["code"])) == strtoupper(($_SESSION["VerifyCode"]))){ <🎜> print("Verification code is correct,"); <🎜> }else{ <🎜> Print("Verification code error,"); <🎜> }<🎜> <🎜>?> Now we have completed the entire process from generating and using verification code images, which can be considered as covering everything from getting started with PHP to mastering verification codes. http://www.bkjia.com/PHPjc/631625.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/631625.htmlTechArticleIt is quite simple to generate a verification code image in php, because the graphic gd is provided for us in php .dll library, to enable the gd graphics library we only need to put the ; in front of php-gd in php.ini...