php实现自动生成验证码的实例讲解_php技巧_

createPNG(); class idCode{ private $words = array('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','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', '0','1','2','3','4','5','6','7','8','9'); private $fonts; private $count;//验证码字符数 private $height; private $width; private $path = '..\myfolder\fonts'; private $keys; //构造函数 public function __construct($count,$width,$height){ $this->count = $count; $this->getFonts(); $this->height = $height; $this->width = $width; } private function getFonts(){ $dir = dir($this->path); while(false !== ($file = $dir->read())){ if($file != '.' && $file != '..'){ $this->fonts[count($this->fonts)] = basename($file); } } $dir->close(); } private function createKeys(){ for($i = 0;$i < $this->count;$i++){ $this->keys[$i]['char'] = $this->words[rand(0,count($this->words)-1)]; //使用字体路径标识 $this->keys[$i]['filename'] = $this->path.'\\'.$this->fonts[rand(0,count($this->fonts)-1)]; } } public function createPNG(){ $this->createKeys(); //创建画布以及颜色块儿 $bg = imagecreatetruecolor($this->width + 10*2,$this->height + 3*2);//两边留10px空白,上下3px $grey = imagecolorallocate($bg,155,155,155); $blue = imagecolorallocate($bg,0x00,0x00,0xff); //填充背景 imagefill($bg,0,0,$grey); //添加字符 $pwidth = $this->width/$this->count; $x;$y; for($i = 0;$i < $this->count;$i++){ $rotation = rand(-40,40);//偏转角度±40° $fontsize = 33; $width_txt; $height_txt; do{ $fontsize--; $bbox = imagettfbbox($fontsize,$rotation,$this->keys[$i]['filename'],$this->keys[$i]['char']); $width_txt = $bbox[2] - $bbox[0];//x 0 2 4 6,y1 3 5 7;左下，右下，右上，左上 $height_txt = $bbox[7] - $bbox[1]; }while($fontsize > 8 && ($height_txt > $this->height || $width_txt > $pwidth)); $fontcolor = imagecolorallocate($bg,rand(0,255),rand(0,255),rand(0,255)); $x = 8 + $pwidth*$i + $pwidth/2 - $width_txt/2;//x坐标基本位置 $y = $this->height/2 - $height_txt/2; imagettftext($bg,$fontsize,$rotation,$x,$y,$fontcolor,$this->keys[$i]['filename'],$this->keys[$i]['char']); } //绘制干扰线 //根据字体酌情增加干扰线 imageline($bg,0,15,40,10,$blue); //图像输出头文件 header('Content-type:image/png'); //输出png图像 imagepng($bg); //清除缓存资源 imagedestroy($bg); } public function checkKeys($input){ if(count($input)!=$this->count){ return 'ERROR:长度不正确.'; }else{ for($i=0;$i < $this->count;$i++){ //0 o O I l 1 校准,根据所选择的字体确定是否需要手动校准 if($input[$i] != $this->keys[$i]['char']){ return 'SUCCESS.'; }else{ return 'ERROR:请输入正确验证码.'; } } } } } ?>