Click php to refresh the verification code

This article mainly introduces how php can refresh the verification code by clicking it. The code is very detailed and is worth learning. If you are interested, please refer to it.

This article mainly introduces how php can refresh the verification code by clicking it. The code is very detailed and is worth learning. If you are interested, please refer to it.

Verification code file CreateImg. class. php

<? Phpclass ValidationCode {private $ width, $ height, $ codenum; public $ checkcode; // generated Verification Code private $ checkimage; // Verification Code image private $ disturbColor = ''; // interfere with the pixel function _ construct ($ width = '80', $ height = '20', $ codenum = '4') {$ this-> width = $ width; $ this-> height = $ height; $ this-> codenum = $ codenum;} function outImg () {// output header $ this-> outFileHeader (); // generate a verification code $ this-> createCode (); // generate an image $ this-> createImage (); // set the interference pixel $ this-> setDi SturbColor (); // write the verification code $ this-> writeCheckCodeToImage (); imagepng ($ this-> checkimage); imagedestroy ($ this-> checkimage );} private function outFileHeader () {header ("Content-type: image/png");} private function createCode () {$ this-> checkcode = strtoupper (substr (md5 (rand (), 0, $ this-> codenum);} private function createImage () {$ this-> checkimage = @ imagecreate ($ this-> width, $ this-> height); $ back = imagecolora Llocate ($ this-> checkimage, 255,255,255); $ border = imagecolorallocate ($ this-> checkimage, 0, 0); imagefilledrectangle ($ this-> checkimage, 0, 0, $ this-> width-1, $ this-> height-1, $ back); // white background imagerectangle ($ this-> checkimage, $ this-> width-1, $ this-> height-1, $ border); // black border} private function setDisturbColor () {for ($ I = 0; $ I <= 200; $ I ++) {$ this-> disturbColor = imagecolorallocate ($ this-> checkimage, rand (0,255), rand (0,255), rand (0,255); imagesetpixel ($ this-> checkimage, rand (2,128), rand ), $ this-> disturbColor) ;}} private function writeCheckCodeToImage () {for ($ I = 0; $ I <=$ this-> codenum; $ I ++) {$ bg_color = imagecolorallocate ($ this-> checkimage, rand (0,255), rand (0,128), rand (0,255 )); $ x = floor ($ this-> width/$ this-> codenum) * $ I; $ y = rand (0, $ this-> height-15 ); imagechar ($ this-> checkimage, rand (5, 8), $ x, $ Y, $ this-> checkcode [$ I], $ bg_color) ;}} function _ destruct () {unset ($ this-> width, $ this-> height, $ this-> codenum) ;}}?>

Contains the file imgcode. php

<? Php session_start (); require_once ('createimg. class. php '); $ image = new ValidationCode ('80', '20', '4'); // image length, width, and number of characters $ image-> outImg (); $ _ SESSION ['validationcode'] = $ image-> checkcode; // store the verification code to $ _ SESSION?>

Front-End file demo. php

? Php session_start (); $ test =$ _ POST ['test']; $ test = strtoupper (trim ($ test )); $ submit = $ _ POST ['submit ']; if (isset ($ submit) {if ($ test = $ _ SESSION ['validationcode']) {echo 'true';} else {echo 'false'; }}?> Image