在本篇文章里小编给大家整顿了一篇对于php实现主动生成验证码的实例解说内容，有须要的敌人们能够跟着学习下。
当初验证码在表单中的利用越来越多了，然而如果用js来实现总感觉不太不便，因而应用php来实现下，在此记录下。
当然，咱们也能够封装成一个函数，当前应用的时候也是很不便的，这里并未封装，感兴趣的小伙伴能够本人封装下。
具体实现代码：
新建一个cap_sz.php文件：
<?phpsession_start(); //设置session,肯定要在顶部$width = 150; //设置图片宽为300像素$height = 40; //设置图片高为40像素$image = imagecreatetruecolor($width, $height); //设置验证码大小的函数$bgcolor = imagecolorallocate($image, 255, 255, 255); //验证码色彩RGB为(255,255,255)#ffffffimagefill($image, 0, 0, $bgcolor); //区域填充$cap_code = "";for($i=0;$i<4;$i++){ $fontsize = 7; //设置字体大小 $fontcolor = imagecolorallocate($image, rand(0,120), rand(0,120), rand(0,120)); //数字越大，色彩越浅，这里是深色彩0-120 $fontcontent = rand(0,9); $cap_code.=$fontcontent; //.=间断定义变量 $x = ($i*150/4)+rand(5,10); $y = rand(5,10); //设置坐标 imagestring($image, $fontsize, $x, $y, $fontcontent, $fontcolor);}$_SESSION['code'] = $cap_code; //存到session//设置烦扰元素，设置雪花点for($i=0;$i<300;$i++){ $inputcolor = imagecolorallocate($image, rand(50,200), rand(20,200), rand(50,200)); //设置色彩，20-200色彩比数字浅，不烦扰浏览 imagesetpixel($image, rand(1,149), rand(1,39), $inputcolor); //画一个繁多像素的元素}//减少烦扰元素，设置横线(先设置线的色彩，在设置横线)for ($i=0;$i<4;$i++) { $linecolor = imagecolorallocate($image, rand(20,220), rand(20,220),rand(20,220)); //设置线的色彩 imageline($image, rand(1,149), rand(1,39), rand(1,299), rand(1,149), $linecolor); } //因为有些浏览器，拜访的content-type会是文本型（乱码），所以咱们须要设置成图片的格局类型header('Content-Type:image/png');imagepng($image); //建设png函数imagedestroy($image); //完结图形函数，打消$image实例扩大：
<?php$iC = new idCode(5,60,30);$iC->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)]; //应用字体门路标识 $this->keys[$i]['filename'] = $this->path.'\\'.$this->fonts[rand(0,count($this->fonts)-1)]; } } public function createPNG(){ $this->createKeys(); //创立画布以及色彩块儿 $bg = imagecreatetruecolor($this->width + 10*2,$this->height + 3*2);//两边留10px空白,高低3px $grey = imagecolorallocate($bg,155,155,155); $blue = imagecolorallocate($bg,0x00,0x00,0xff); //填充背景 imagefill($bg,0,0,$grey); //增加字符 $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坐标根本地位 $y = $this->height/2 - $height_txt/2; imagettftext($bg,$fontsize,$rotation,$x,$y,$fontcolor,$this->keys[$i]['filename'],$this->keys[$i]['char']); } //绘制烦扰线 //依据字体酌情减少烦扰线 imageline($bg,0,15,40,10,$blue); //图像输入头文件 header('Content-type:image/png'); //输入png图像 imagepng($bg); //革除缓存资源 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,依据所抉择的字体确定是否须要手动校准 if($input[$i] != $this->keys[$i]['char']){ return 'SUCCESS.'; }else{ return 'ERROR:请输出正确验证码.'; } } } }}?>