帮你找了个PHP最简单的验证码图片生成验证流程,供参考:
<?php
session_start();
//生成验证码图片
header("Content-type: image/png");
// 全数字
$str = "1,2,3,4,5,6,7,8,9,a,b,c,d,f,g"; //要显示的字符
$list = explode(",", $str);
$cmax = count($list) - 1;
$verifyCode = '';
for ( $i=0; $i < 5; $i++ ){
$randnum = mt_rand(0, $cmax);
$verifyCode .= $list[$randnum]; //取出字符
}
$_SESSION['code'] = $verifyCode; //放入SESSION中
$im = imagecreate(58,28); //生成图片
$black = imagecolorallocate($im, 0,0,0); //此条及以下三条为设置的颜色
$white = imagecolorallocate($im, 255,255,255);
$gray = imagecolorallocate($im, 200,200,200);
$red = imagecolorallocate($im, 255, 0, 0);
imagefill($im,0,0,$white); //给图片填充颜色
//将验证码绘入图片
imagestring($im, 5, 10, 8, $verifyCode, $black); //将验证码写入到图片中
for($i=0;$i<50;$i++) //加入干扰象素
{
imagesetpixel($im, rand()p , rand()0 , $black); //加入点状干扰素
imagesetpixel($im, rand()p , rand()0 , $red);
imagesetpixel($im, rand()p , rand()0 , $gray);
//imagearc($im, rand()p, rand()p, 20, 20, 75, 170, $black); //弧线干扰
//imageline($im, rand()p, rand()p, rand()p, rand()p, $red); //线条干扰
}
imagepng($im);
imagedestroy($im);
?>
调用方式
<form action="act.php" method="post">
<input type="text" name="code" />
<img id="code" src="create_code.php" alt="看不清楚,换一张" onClick="create_code()"/>
<!--<button type="button" onClick="create_code()">更换</button>-->
<button type="submit">提交</button>
</form>
<script>
function create_code(){
document.getElementByIdx_x('code').src = 'create_code.php?'+Math.random()*10000;
}
</script>
//处理,判断是否输入正确
action.php
<?php
session_start();
if($_POST['code'] == $_SESSION['code']){
echo 'ok';
}else{
echo 'no';
}
?>