PHP ci framework verification code example analysis_PHP tutorial

php code:

Copy code The code is as follows:

class Captcha_code
{
var $width='60';
var $num='4';
var $height='20';
var $name='randcode';
public function __construct($ conf="")
{
if($conf!="")
{
foreach($conf as $key=>$value)
{
$this ->$key=$value;
}
}
}

function show()
{
Header("Content-type: image/gif") ;
/*
* Initialization
*/
$border = 0; //Whether border 1 is required: 0 or not
$how = $this->num; //Verification Number of code points
$w = $this->width; //Picture width
$h = $this->height; //Picture height
$fontsize = 5; //Font size
$alpha = "abcdefghijkmnopqrstuvwxyz"; //Verification code content 1: Letters
$number = "023456789"; //Verification code content 2: Numbers
$randcode = ""; //Verification code string Initialization
srand((double)microtime()*1000000); //Initialize random number seed

$im = ImageCreate($w, $h); //Create verification image

/*
* Draw the basic frame
*/
$bgcolor = ImageColorAllocate($im, 255, 255, 255); //Set the background color
ImageFill($im, 0, 0, $bgcolor); //Fill the background color
if($border)
{
$black = ImageColorAllocate($im, 0, 0, 0); //Set the border color
ImageRectangle($ im, 0, 0, $w-1, $h-1, $black);//Draw the border
}

/*
* Generate random characters bit by bit
*/
for($i=0; $i<$how; $i++)
{
$alpha_or_number = mt_rand(0, 1); //Letters or numbers
$str = $alpha_or_number? $alpha : $number;
$which = mt_rand(0, strlen($str)-1); //Which character to take
$code = substr($str, $which, 1); //Get Character
$j = !$i ? 4: $j+15; //Draw character position
$color3 = ImageColorAllocate($im, mt_rand(0,100), mt_rand(0,100), mt_rand(0,100)); //Characters are then colored
ImageChar($im, $fontsize, $j, 3, $code, $color3); //Draw characters
$randcode .= $code; //Add verification code characters bit by bit String
}

/*
* Add interference
*/
for($i=0; $i<5; $i++)//Draw background interference lines
{
$color1 = ImageColorAllocate($im, mt_rand(0,255), mt_rand(0,255), mt_rand(0,255)); //Interference line color
ImageArc($im, mt_rand(-5,$w) , mt_rand(-5,$h), mt_rand(20,300), mt_rand(20,200), 55, 44, $color1); //Interference line
}
for($i=0; $i<$ how*15; $i++)//Draw background interference points
{
$color2 = ImageColorAllocate($im, mt_rand(0,255), mt_rand(0,255), mt_rand(0,255)); //Color of interference points
ImageSetPixel($im, mt_rand(0,$w), mt_rand(0,$h), $color2); //Interference point
}

//Write the verification code string session

//$this->session->set_userdata(array($this->name=>$randcode));

$_SESSION[$this-> name]=$randcode;
/*End of drawing*/
Imagegif($im);
ImageDestroy($im);
/*End of drawing*/
}
}
?>

Call the php code:

Copy the code The code is as follows:

function verify_image() {
$conf['name'] = 'verify_code'; //As a configuration parameter
$this->load->library('lib_captcha', $conf);
        $this->lib_captcha->show();
             $yzm_session = $this->session->userdata('verify_code');                                                                         $yzm_session;

html code:

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The code is as follows:

                                                          < "verify_text" class="yzma" value="">
                                                                                                                                         Change one
                                                                                                                                   ;b>The verification code is incorrect
                                                                                                                                                 🎜>js code:



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The code is as follows:

http://www.bkjia.com/PHPjc/327905.html

www.bkjia.com

true

http: //www.bkjia.com/PHPjc/327905.html

TechArticlephp code: Copy the code as follows: ?php class Captcha_code { var $width='60'; var $num ='4'; var $height='20'; var $name='randcode'; public function __construct($conf="") { if($...