PHP Verification Code of digital operation verification Code

<?php//If you don't understand the code, please see my previous article for a detailed answer. Digital Verification Code: http://my.oschina.net/u/2391943/blog/485163getValidate (100,30); Function getvalidate ($w, $h) {$img  = imagecreate ($w, $h); $gray  = imagecolorallocate ($img, 255,255,255); $black  =  Imagecolorallocate ($img, Rand (0,200), Rand (0,200), Rand (0,200)), $red  = imagecolorallocate ($img,  255, 0, 0); $white  = imagecolorallocate ($img,  255, 255, 255); $green  =  imagecolorallocate ($img,  0, 255, 0); $blue  = imagecolorallocate ($img,  0,  0, 255) Imagefilledrectangle ($img, 0, 0, 100, 30,  $black); for ($i  =  0; $i  < 80; $i + +) {Imagesetpixel ($img,  rand (0, $w),  rand (0, $h),  $gray);} $num 1 = rand (1,99), $num 2 = rand (1,99); Imagestring ($img,  5, 5, rand (1,10),   $num 1,  $red) imagestring ($img, 5,30,rand (1,10), Getrand (),  $white), imagestring ($img, 5,45,rand ( 1,10), $num2,  $green); imagestring ($img, 5,65,rand (1,10), "=",  $blue), imagestring ($img, 5,80,rand (1,10), "?",   $red), header ("Content-type:image/png"); Imagepng ($img); Imagedestroy ($img);} Function getrand () {$code  = rand (0,1);switch  ($code)  {case 0:return  "+"; break;case 1:return  "-"; break;default:# code...break;}}? >

Zhongzhiyuan Jiangsu Nanjing Zhongzhiyuan

PHP Verification Code of digital operation verification Code