php 生产验证码

<?php/** * 生成验证码 * @author chenzhouyu * 类用法 * $checkcode = new checkcode(); * $checkcode->doimage(); * //取得验证 * $_SESSION['code']=$checkcode->get_code(); */class checkcode {//验证码的宽度public $width=130;//验证码的高public $height=50;//设置字体的地址private $font;//设置字体色public $font_color;//设置随机生成因子public $charset = 'abcdefghkmnprstuvwyzABCDEFGHKLMNPRSTUVWYZ23456789';//设置背景色public $background = '#EDF7FF';//生成验证码字符数public $code_len = 5;//字体大小public $font_size = 20;//验证码private $code;//图片内存private $img;//文字X轴开始的地方private $x_start;function __construct() {$rand = rand(0,1);if($rand==0) {$this->font = PC_PATH.'libs'.DIRECTORY_SEPARATOR.'data'.DIRECTORY_SEPARATOR.'font'.DIRECTORY_SEPARATOR.'elephant.ttf';} else {$this->font = PC_PATH.'libs'.DIRECTORY_SEPARATOR.'data'.DIRECTORY_SEPARATOR.'font'.DIRECTORY_SEPARATOR.'Vineta.ttf';}}/** * 生成随机验证码。 */protected function creat_code() {$code = '';$charset_len = strlen($this->charset)-1;for ($i=0; $i<$this->code_len; $i++) {$code .= $this->charset[rand(1, $charset_len)];}$this->code = $code; return $code;}/** * 获取验证码 */public function get_code() {return strtolower($this->code);}/** * 生成图片 */public function doimage() {$code = $this->creat_code();$this->img = imagecreatetruecolor($this->width, $this->height);if (!$this->font_color) {$this->font_color = imagecolorallocate($this->img, rand(0,156), rand(0,156), rand(0,156));} else {$this->font_color = imagecolorallocate($this->img, hexdec(substr($this->font_color, 1,2)), hexdec(substr($this->font_color, 3,2)), hexdec(substr($this->font_color, 5,2)));}//设置背景色$background = imagecolorallocate($this->img,hexdec(substr($this->background, 1,2)),hexdec(substr($this->background, 3,2)),hexdec(substr($this->background, 5,2)));//画一个柜形，设置背景颜色。imagefilledrectangle($this->img,0, $this->height, $this->width, 0, $background);$this->creat_font();$this->creat_line();$this->output();}/** * 生成文字 */private function creat_font() {$x = $this->width/$this->code_len;for ($i=0; $i<$this->code_len; $i++) {imagettftext($this->img, $this->font_size, rand(-30,30), $x*$i+rand(0,5), $this->height/1.4, $this->font_color, $this->font, $this->code[$i]);if($i==0)$this->x_start=$x*$i+5;}}/** * 画线 */private function creat_line() {imagesetthickness($this->img, 3);    $xpos   = ($this->font_size * 2) + rand(-5, 5);    $width  = $this->width / 2.66 + rand(3, 10);    $height = $this->font_size * 2.14;    if ( rand(0,100) % 2 == 0 ) {      $start = rand(0,66);      $ypos  = $this->height / 2 - rand(10, 30);      $xpos += rand(5, 15);    } else {      $start = rand(180, 246);      $ypos  = $this->height / 2 + rand(10, 30);    }    $end = $start + rand(75, 110);    imagearc($this->img, $xpos, $ypos, $width, $height, $start, $end, $this->font_color);    if ( rand(1,75) % 2 == 0 ) {      $start = rand(45, 111);      $ypos  = $this->height / 2 - rand(10, 30);      $xpos += rand(5, 15);    } else {      $start = rand(200, 250);      $ypos  = $this->height / 2 + rand(10, 30);    }    $end = $start + rand(75, 100);    imagearc($this->img, $this->width * .75, $ypos, $width, $height, $start, $end, $this->font_color);}/** * 输出图片 */private function output() {header("content-type:image/png\r\n");imagepng($this->img);imagedestroy($this->img);}}

在前台显示结果为：