本文為大家分享了php圖片驗(yàn)證碼的實(shí)現(xiàn)代碼，分享給大家供大家參考，具體內(nèi)容如下
1.驗(yàn)證碼圖片生成
captcha.php
//1.生成100*30大小的圖片,默認(rèn)為黑色$image = imagecreatetruecolor(100,30);//創(chuàng)建白色底圖$bgcolor = imagecolorallocate($image,255,255,255);//用白色填充黑色imagefill ($image,0,0,$bgcolor);//2.隨機(jī)顯示數(shù)字或字母$captch_code = "";for($i=0;$i<4;$i++){ $fontsize=6; $fontcolor=imagecolorallocate($image,rand(0,120),rand(0,120),rand(0,120)); $data = "abcdefghijkmnpqrstuvwxy3456789"; $fontcontent =substr($data,rand(0,strlen($data)),1); $captch_code .=$fontcontent; $x = ($i*100/4)+rand(5,10); $y = rand(5,10); imagestring($image, $fontsize, $x, $y, $fontcontent,$fontcolor);}$_SESSION["authcode"] = $captch_code;//3.增加干擾//干擾點(diǎn)for($i=0;$i<100;$i++){ $pointcolor=imagecolorallocate($image,rand(50,200),rand(50,200),rand(50,200)); imagesetpixel($image,rand(1,99),rand(1,29),$pointcolor);}//干擾線for($i=0;$i<2;$i++){ $linecolor=imagecolorallocate($image,rand(80,220),rand(80,220),rand(80,220)); imageline($image,rand(1,99),rand(1,29),rand(1,99),rand(1,29),$linecolor);}header("content-type:image/png");imagepng($image); 2.頁(yè)面實(shí)現(xiàn)驗(yàn)證碼功能
form.php
<?phpif(isset($_POST["authcode"])){ session_start(); if(strtolower($_POST["authcode"])==$_SESSION["authcode"]){ echo "OK"; }else{ echo "NO"; }}?><!doctype html><html lang="en"><head> <meta charset="UTF-8"> <title>Document</title></head><body><form action="form.php" method="post"> <p>驗(yàn)證碼圖片: <img id="img" border="1" src="captcha.php?r=<?php echo rand()?>" <a href="javascript:void(0)" onclick="document.getElementById('img').src='captcha.php?r'+Math.random() ">換一個(gè)</a> </p> <p><input type="text" name="authcode"></p> <p><input type="submit" value="提交"></p></form></body></html> 以上就是本文的全部?jī)?nèi)容，幫助大家輕松實(shí)現(xiàn)php圖片驗(yàn)證碼。
