PHP验证码

来源：互联网发布：司令部升级数据编辑：程序博客网时间：2024/05/17 02:12

<?php

Header("Content-type: image/PNG");

//初始化

$border = 1; //是否要边框 1要:0不要

$how = 5; //验证码位数

$w = $how*13; //图片宽度

$h = 20; //图片高度

$fontsize = 5; //字体大小

$array="0123456789"; //随机字符

$seccode = ""; //验证码字符串初始化

srand((double)microtime()*1000000); //初始化随机数种子

$im = ImageCreate($w, $h); //创建验证图片

//绘制基本框架

$bgcolor = ImageColorAllocate($im, 255, 255, 255); //设置背景颜色

ImageFill($im, 0, 0, $bgcolor); //填充背景色

if($border) {

$black = ImageColorAllocate($im, 0, 0, 0); //设置边框颜色

ImageRectangle($im, 0, 0, $w-1, $h-1, $black); //绘制边框

}

//逐位产生随机字符

for($i=0; $i<$how; $i++) {

$code = substr($array,rand(0,strlen($array)-1),1); //取字符

$j = !$i ? 4 : $j+12; //绘字符位置

$color3 = ImageColorAllocate($im, mt_rand(0,100), mt_rand(0,100), mt_rand(0,100)); //字符随即颜色

ImageChar($im, $fontsize, $j, 3, $code, $color3); //绘字符

$seccode .= $code; //逐位加入验证码字符串

}

//添加干扰

for($i=0; $i<5; $i++) { //绘背景干扰线

$color1 = ImageColorAllocate($im, mt_rand(0,255), mt_rand(0,255), mt_rand(0,255)); //干扰线颜色

ImageArc($im, mt_rand(-5,$w), mt_rand(-5,$h), mt_rand(20,300), mt_rand(20,200), 55, 44, $color1); //干扰线

}

for($i=0; $i<$how*40; $i++){ //绘背景干扰点

$color2 = ImageColorAllocate($im, mt_rand(0,255), mt_rand(0,255), mt_rand(0,255)); //干扰点颜色

ImageSetPixel($im, mt_rand(0,$w), mt_rand(0,$h), $color2); //干扰点

}

//把验证码字符串写入session

session_start();

$_SESSION['seccode'] = $seccode;

/*绘图结束*/

Imagegif($im);

ImageDestroy($im);

/*绘图结束*/

验证页面

<?php

session_start();

$type=$_POST['type'];

if($type=="seccode") {

if($_SESSION['seccode']==$_POST['SEC']) {

echo "验证码正确";

} else {

echo "验证码错误";

}

} elseif($type=="Username") {

if($_POST['SEC']=="a") {

echo "用户名正确";

} else {

echo "用户名错误";

}

} elseif($type=="Password") {

if($_POST['SEC']=="b") {

echo "密码正确";

} else {

echo "密码错误";

}

调用

<head>

.checkcode

{

cursor: pointer;

}

</style>

function check(pp,type) {

Ajax.sendurl="d.php?authnum="+Math.random();

Ajax.method="post";

Ajax.contentid="Err";

Ajax.loadingid="Err";

Ajax.loading='数据加载中，请稍候...'

Ajax.sendstr="type="+type+"&SEC="+document.getElementById(pp).value;

Ajax.send();

}

function seccode() {

check("SEC","seccode");

}

function username() {

check("USer","Username");

}

function password() {

check("Pass","Password");

}

</script>

</head>

<body>

<br />

<img src="c.php?authnum=123456789" onclick="this.src='c.php?authnum='+Math.random()"

alt="如果不认识点击图片刷新" class="checkcode" /><br />

Check</button>

<br />

Check</button>

Check</button>

</body>

</html>