php验证码生成程序代码_PHP教程

class ValidationCode
{
//属性
private $width;
private $height;
private $codeNum;
private $image;
private $disturbColorNum; //干扰元素数目
private $checkCode;
function __construct($width=80,$height=20,$codeNum=4)
{
$this->width=$width;
$this->height=$height;
$this->codeNum=$codeNum;
$number=floor($width*$height/15);
if($number>240-$codeNum)
{
$this->disturbColorNum=240-$codeNum;
}else
{
$this->disturbColorNum=$number;
}
$this->checkCode=$this->createCheckcode();
}
function getCheckCode()
{
return $this->checkCode;
}
private function createImage(){
$this->image=imagecreatetruecolor($this->width,$this->height);
$backcolor=imagecolorallocate($this->image,rand(225,255),rand(225,255),rand(255,255));
imagefill($this->image,0,0,$backcolor);
$border=imagecolorallocate($this->image,0,0,0);
imagerectangle($this->image,0,0,$this->width-1,$this->height-1,$border);
}
private function setDisturbColor(){
for($i=0;$i<$this->disturbColorNum;$i++){
$color=imagecolorallocate($this->image,rand(0,255),rand(0,255),rand(0,255));
imagesetpixel($this->image,rand(1,$this->width-2),rand(1,$this->height-2),$color);
}
for($i=0;$i<10;$i++)
{
$color=imagecolorallocate($this->image,rand(0,255),rand(0,255),rand(0,255));
imagearc($this->image,rand(-10,$this->width),rand(-10,$this->height),rand(30,300),rand(20,300),55,44,$color);
}
}
private function outputText($fontFace=""){
for($i=0;$i<$this->codeNum;$i++)
{
$fontcolor=imagecolorallocate($this->image,rand(0,128),rand(0,128),rand(0,128));
if($fontFace=="")
{
$fontsize=rand(3,5);
$x=floor($this->width/$this->codeNum)*$i+5;
$y=rand(0,$this->height-15);
imagechar($this->image,$fontsize,$x,$y,$this->checkCode{$i},$fontcolor);
}
else
{
$fontsize=rand(12,16);
$x=floor(($this->width-8)/$this->codeNum)*$i+8;
$y=rand($fontsize,$this->height-8);
imagettftext($this->image,$fontsize,rand(-45,45),$x,$y,$fontcolor,$fontFace,$this->checkCode{$i});
}
}
}

private function createCheckCode(){
$code="23456789abcdefghijkmnpqrstuvwrst";
$str="";
for($i=0;$i<$this->codeNum;$i++)
{
$char=$code{rand(0,strlen($code)-1)};
$str.=$char;
}
return $str;
}
private function outputImage()
{
if(imagetypes()&IMG_GIF)
{
header("Content-Type:image/gif");
imagepng($this->image);
}else if(imagetypes()&IMG_JPG)
{
header("Content-Type:image/jpeg");
imagepng($this->image);
}else if(imagetypes()&IMG_PNG)
{
header("Content-Type:image/png");
imagepng($this->image);
}else if(imagetypes()&IMG_WBMP){
header("Content-Type:image/vnd.wap.wbmp");
imagepng($this->image);
}else
{
die("PHP不支持图片验证码");
}
}
//通过该方法向浏览器输出图像
function showImage($fontFace="")
{
//创建图像背景
$this->createImage();
//设置干扰元素
$this->setDisturbColor();
//向图像中随机画出文本
$this->outputText($fontFace);
//输出图像
$this->outputImage();
}

function __destruct()
{
imagedestroy($this->image);
}
}
function checklogin(){
if(empty($_POST['name']))
die( '用户名不能为空');
if(empty($_POST['password']))
die("密码不能为空");
if($_SESSION['code']!=$_POST['vertify'])
die("验证码输入不正确".$_SESSION['code']);

$username=$_POST['name'];
$password=md5($_POST['password']);
//检查是否存在
conndb($username,$password);
}
function conndb($name="",$ps=""){
$conn=mysql_connect('localhost','root','123456');
if(!$conn) die("数据库连接失败".mysql_error());
mysql_select_db('5kan',$conn) or die('选择数据库失败'.mysql_error());
mysql_set_charset('utf8',$conn);
$sql="select id from k_user where username='{$name}' and password='{$ps}'";
$result=mysql_query($sql) or die("SQL语句错误".mysql_error());
if(mysql_num_rows($result)>0) die("登录成功");
else die("用户名或者密码错误");
mysql_close($conn);
}
session_start();
if(!isset($_POST['randnum']))
{
$code=new ValidationCode(120,20,4);
$code->showImage("comicbd.ttf"); //显示在页面
$_SESSION['code']=$code->getCheckCode();//保存在服务器中
}
else
{
checklogin();
}

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