PHP学习笔记09——GD生成验证码实例
vcode.class.php
1 <?php 2 class Vcode{ 3 private $width; 4 private $height; 5 private $codeNum; 6 private $disturbColorNum; //干扰元素数量 7 private $checkCode; 8 private $image; 9 10 //构造方法,参数初始化,并生成验证码 11 function __construct($width = 80, $height = 20, $codeNum = 4) { 12 $this->width = $width; 13 $this->height = $height; 14 $this->codeNum = $codeNum; 15 $number = floor($height * $width / 15); 16 //计算干扰元素数量 17 if ($number > 240 - $codeNum) 18 $this->disturbColorNum = 240 - $codeNum; 19 else 20 $this->disturbColorNum = $number; 21 //创建验证码 22 $this->checkCode = $this->createCheckCode(); 23 } 24 //析构方法,销毁图片资源 25 function __destruct(){ 26 imagedestroy($this->image); 27 } 28 //随机生成验证码 29 private function createCheckCode(){ 30 $code = "3456789abcdeffghijkmnpqrstuvwxyzABCDEFHIJKMNPQRSTUVWXYZ"; 31 $ascii=""; 32 for ($i = 0; $i < $this->codeNum; $i++) { 33 $ascii .= $code{rand(0,strlen($code)-1)}; 34 } 35 return $ascii; 36 } 37 //用于输出验证码图片 38 function __toString(){ 39 $_SESSION["code"] = strtoupper($this->checkCode); 40 $this->outimg(); 41 return ""; 42 } 43 //输出图片的具体步骤 44 private function outimg(){ 45 $this->getCreateImage(); 46 $this->setDisturbcolor(); 47 $this->outputText(); 48 $this->outputImage(); 49 } 50 //初始化图片 51 private function getCreateImage(){ 52 $this->image = imagecreatetruecolor($this->width, $this->height); 53 $backColor = imagecolorallocate($this->image, rand(225,255), rand(225,255), rand(225,255)); 54 imagefill($this->image, 0, 0, $backColor); 55 $borderColor = imagecolorallocate($this->image, 0, 0, 0); 56 imagerectangle($this->image, 0, 0, $this->width-1, $this->height-1, $borderColor); 57 } 58 //输出不同颜色的点作为干扰素,点加弧线 59 private function setDisturbcolor(){ 60 for ($i = 0; $i <= $this->disturbColorNum; $i++) { 61 $color = imagecolorallocate($this->image, rand(0,255), rand(0,255), rand(0,255)); 62 imagesetpixel($this->image, rand(1,$this->width-2), rand(1,$this->height-2), $color); 63 } 64 for ($i = 0; $i <10; $i++) { 65 $color = imagecolorallocate($this->image, rand(0,255), rand(0,255), rand(0,255)); 66 imagearc($this->image, rand(-10,$this->width), rand(-10,$this->height), rand(30,300), 67 rand(20,200), 55, 44, $color); 68 } 69 } 70 //随机在图片中生成字符串 71 private function outputText(){ 72 for ($i = 0; $i < $this->codeNum; $i++) { 73 $fontcolor = imagecolorallocate($this->image, rand(0,128), rand(0,128), rand(0,128)); 74 $fontsize = rand(4, 5); 75 $x = floor($this->width/$this->codeNum)*$i + 3; 76 $y = rand(0, $this->height-imagefontheight($fontsize)); 77 imagechar($this->image, $fontsize, $x, $y, $this->checkCode{$i}, $fontcolor); 78 } 79 } 80 //输出图片 81 private function outputImage(){ 82 header("Content-type: image/png"); 83 imagepng($this->image); 84 } 85 86 } 87 ?>
imgcode.php
1 <?php 2 session_start(); //开启session 3 require_once ('vcode.class.php'); //包含验证码文件 4 echo new Vcode(); 5 ?>
image.php
1 <?php 2 session_start(); //开启session 3 4 if (isset($_POST['submit'])) { 5 if (strtoupper($_POST['code']) == $_SESSION['code']) 6 echo "验证码输入正确<br/>"; 7 else 8 echo '<font color="red">验证码输入错误<font/><br/>'; 9 } 10 ?> 11 <html> 12 <head> 13 <script type="text/javascript"> 14 function newgdcode(obj, url) { 15 //加一个随机参数以免浏览器不刷新 16 obj.src = url+'?nowtime='+new Date().getTime(); 17 } 18 </script> 19 </head> 20 <body> 21 <img alt="看不清楚,换一张" src="imgcode.php" style="cursor: pointer;" 22 onclick="javascript:newgdcode(this, this.src);" /> 23 <form action="image.php" method="post"> 24 <input type="text" size="4" name="code" /> 25 <input type="submit" name="submit" value="提交" /> 26 </form> 27 </body> 28 </html>
执行结果
