驗證碼常用於登陸頁面、留言頁面、注冊頁面,驗證碼的原理很簡單:利用GD庫創建一個圖片,圖片當然要加上必要的干擾碼,然後在服務器端存入SESSION,等用戶提交的時候判斷session是否相同。 代碼如下 復制代碼
<?php
/*
* Captcha Class base on PHP GD Lib
* @author Design
* @version 1.0
* @copyright js8.in 2010
* @demo
* include('captchaClass.php');
* $captchaDemo=new Captcha();
* $captchaDemo->createImage();
*/
class Captcha{
//@定義驗證碼圖片高度
private $height;
//@定義驗證碼圖片寬度
private $width;
//@定義驗證碼字符個數
private $textNum;
//@定義驗證碼字符內容
private $textContent;
//@定義字符顏色
private $fontColor;
//@定義隨機出的文字顏色
private $randFontColor;
//@定義字體大小
private $fontSize;
//@定義字體
private $fontFamily;
//@定義背景顏色
private $bgColor;
//@定義隨機出的背景顏色
private $randBgColor;
//@定義字符語言
private $textLang;
//@定義干擾點數量
private $noisePoint;
//@定義干擾線數量
private $noiseLine;
//@定義是否扭曲
private $distortion;
//@定義扭曲圖片源
private $distortionImage;
//@定義是否有邊框
private $showBorder;
//@定義驗證碼圖片源
private $image;
//@Constructor 構造函數
public function Captcha(){
$this->textNum=4;
$this->fontSize=16;
$this->fontFamily='c:\windows\fontsSIMYOU.ttf';//設置中文字體,可以改成linux的目錄
$this->textLang='en';
$this->noisePoint=30;
$this->noiseLine=3;
$this->distortion=false;
$this->showBorder=false;
}
//@設置圖片寬度
public function setWidth($w){
$this->width=$w;
}
//@設置圖片高度
public function setHeight($h){
$this->height=$h;
}
//@設置字符個數
public function setTextNumber($textN){
$this->textNum=$textN;
}
//@設置字符顏色
public function setFontColor($fc){
$this->fontColor=sscanf($fc,'#%2x%2x%2x');
}
//@設置字號
public function setFontSize($n){
$this->fontSize=$n;
}
//@設置字體
public function setFontFamily($ffUrl){
$this->fontFamily=$ffUrl;
}
//@設置字符語言
public function setTextLang($lang){
$this->textLang=$lang;
}
//@設置圖片背景
public function setBgColor($bc){
$this->bgColor=sscanf($bc,'#%2x%2x%2x');
}
//@設置干擾點數量
public function setNoisePoint($n){
$this->noisePoint=$n;
}
//@設置干擾線數量
public function setNoiseLine($n){
$this->noiseLine=$n;
}
//@設置是否扭曲
public function setDistortion($b){
$this->distortion=$b;
}
//@設置是否顯示邊框
public function setShowBorder($border){
$this->showBorder=$border;
}
//@初始化驗證碼圖片
public function initImage(){
if(empty($this->width)){$this->width=floor($this->fontSize*1.3)*$this->textNum+10;}
if(empty($this->height)){$this->height=$this->fontSize*2;}
$this->image=imagecreatetruecolor($this->width,$this->height);
if(empty($this->bgColor)){
$this->randBgColor=imagecolorallocate($this->image,mt_rand(100,255),mt_rand(100,255),mt_rand(100,255));
}else{
$this->randBgColor=imagecolorallocate($this->image,$this->bgColor[0],$this->bgColor[1],$this->bgColor[2]);
}
imagefill($this->image,0,0,$this->randBgColor);
}
//@產生隨機字符
public function randText($type){
$string='';
switch($type){
case 'en':
$str='ABCDEFGHJKLMNPQRSTUVWXY3456789';
for($i=0;$i<$this->textNum;$i++){
$string=$string.','.$str[mt_rand(0,29)];
}
break;
case 'cn':
for($i=0;$i<$this->textNum;$i++) {
$string=$string.','.chr(rand(0xB0,0xCC)).chr(rand(0xA1,0xBB));
}
$string=iconv('GB2312','UTF-8',$string); //轉換編碼到utf8
break;
}
return substr($string,1);
}
//@輸出文字到驗證碼
public function createText(){
$textArray=explode(',',$this->randText($this->textLang));
$this->textContent=join('',$textArray);
if(empty($this->fontColor)){
$this->randFontColor=imagecolorallocate($this->image,mt_rand(0,100),mt_rand(0,100),mt_rand(0,100));
}else{
$this->randFontColor=imagecolorallocate($this->image,$this->fontColor[0],$this->fontColor[1],$this->fontColor[2]);
}
for($i=0;$i<$this->textNum;$i++){
$angle=mt_rand(-1,1)*mt_rand(1,20);
imagettftext($this->image,$this->fontSize,$angle,5+$i*floor($this->fontSize*1.3),floor($this->height*0.75),$this->randFontColor,$this->fontFamily,$textArray[$i]);
}
}
//@生成干擾點
public function createNoisePoint(){
for($i=0;$i<$this->noisePoint;$i++){
$pointColor=imagecolorallocate($this->image,mt_rand(0,255),mt_rand(0,255),mt_rand(0,255));
imagesetpixel($this->image,mt_rand(0,$this->width),mt_rand(0,$this->height),$pointColor);
}
}
//@產生干擾線
public function createNoiseLine(){
for($i=0;$i<$this->noiseLine;$i++) {
$lineColor=imagecolorallocate($this->image,mt_rand(0,255),mt_rand(0,255),20);
imageline($this->image,0,mt_rand(0,$this->width),$this->width,mt_rand(0,$this->height),$lineColor);
}
}
//@扭曲文字
public function distortionText(){
$this->distortionImage=imagecreatetruecolor($this->width,$this->height);
imagefill($this->distortionImage,0,0,$this->randBgColor);
for($x=0;$x<$this->width;$x++){
for($y=0;$y<$this->height;$y++){
$rgbColor=imagecolorat($this->image,$x,$y);
imagesetpixel($this->distortionImage,(int)($x+sin($y/$this->height*2*M_PI-M_PI*0.5)*3),$y,$rgbColor);
}
}
$this->image=$this->distortionImage;
}
//@生成驗證碼圖片
public function createImage(){
$this->initImage(); //創建基本圖片
$this->createText(); //輸出驗證碼字符
if($this->distortion){$this->distortionText();} //扭曲文字
$this->createNoisePoint(); //產生干擾點
$this->createNoiseLine(); //產生干擾線
if($this->showBorder){imagerectangle($this->image,0,0,$this->width-1,$this->height-1,$this->randFontColor);} //添加邊框
imagepng($this->image);
imagedestroy($this->image);
if($this->distortion){imagedestroy($this->$distortionImage);}
return $this->textContent;
}
}
?>使用方法:
<?php
//session_start();
header("Content-type:image/png");
include('captcha5_class.php');
$captcha5=new Captcha();
//@設置驗證碼寬度
//$captcha5->setWidth(200);
//@設置驗證碼高度
//$captcha5->setHeight(50);
//@設置字符個數
$captcha5->setTextNumber(5);
//@設置字符顏色
//$captcha5->setFontColor('#ff9900');
//@設置字號大小
//$captcha5->setFontSize(25);
//@設置字體
$captcha5->setFontFamily('c:\windows\fonts\STXINGKA.TTF');
//@設置語言
$captcha5->setTextLang('cn');
//@設置背景顏色
//$captcha5->setBgColor('#000000');
//@設置干擾點數量
//$captcha5->setNoisePoint(600);
//@設置干擾線數量
//$captcha5->setNoiseLine(10);
//@設置是否扭曲
//$captcha5->setDistortion(true);
//@設置是否顯示邊框
$captcha5->setShowBorder(true);
//輸出驗證碼
$code=$captcha5->createImage();
//$_SESSION['captchaCode']['content']=$code;
//$_SESSION['captchaCode']['time']=microtime();
?>