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Use GD library to do verification code in php, phpgd library verification code_PHP tutorial
Use GD library to do verification code in php, phpgd library verification code_PHP tutorial
Use GD library for verification code in php, phpgd library verification code
<?php
require_once 'string.func.php';
//通过GD库做验证码
/**
*添加验证文字
* @param int $type
* @param int $length
*/
function buildRandomString($type=1,$length=4){
$row='';
if($type==1){
$row=join('',range(0, 9));
}else if($type==2){
$row=join('', array_merge(range('a','z'),range('A', 'Z')));
}else if($type==3){
$row=join('', array_merge(range('a','z'),range('A', 'Z'),range(0, 9)));
};
$row=str_shuffle($row);
$row=substr($row,0,$length);
return $row;
}
/**
* 生成缩略图
* @param int $type //包含数字或者英文
* @param int $length 多少个字符
* @param int $pixel 干扰小点的密度
* @param int $dst_h 干扰线的密度
* @param string //验证码在$_SESSION中的名字
*/
function verifyImage($type=1,$length=4,$pixel=0,$line=0,$sess_name = "verify"){
//session_start();
//创建画布
$width = 100;
$height = 40;
$image = imagecreatetruecolor ( $width, $height );
$white = imagecolorallocate ( $image, 255, 255, 255 );
$black = imagecolorallocate ( $image, 0, 0, 0 );
//用填充矩形填充画布
imagefilledrectangle ( $image, 1, 1, $width - 2, $height - 2, $white );
$chars = buildRandomString ( $type, $length );
$_SESSION [$sess_name] = $chars;
//$fontfiles = array ("MSYH.TTF", "MSYHBD.TTF", "SIMLI.TTF", "SIMSUN.TTC", "SIMYOU.TTF", "STZHONGS.TTF" );
$fontfiles = array ("SIMKAI.TTF" );
//由于字体文件比较大,就只保留一个字体,如果有需要的同学可以自己添加字体,字体在你的电脑中的fonts文件夹里有,直接运行输入fonts就能看到相应字体
for($i = 0; $i < $length; $i ++) {
$size = mt_rand ( 14, 18 );
$angle = mt_rand ( - 15, 15 );
$x = 5 + $i * $size;
$y = mt_rand ( 20, 26 );
$fontfile = "../fonts/" . $fontfiles [mt_rand ( 0, count ( $fontfiles ) - 1 )];
$color = imagecolorallocate ( $image, mt_rand ( 50, 90 ), mt_rand ( 80, 200 ), mt_rand ( 90, 180 ) );
$text = substr ( $chars, $i, 1 );
imagettftext ( $image, $size, $angle, $x, $y, $color, $fontfile, $text );
}
if ($pixel) {
for($i = 0; $i < 50; $i ++) {
imagesetpixel ( $image, mt_rand ( 0, $width - 1 ), mt_rand ( 0, $height - 1 ), $black );
}
}
if ($line) {
for($i = 1; $i < $line; $i ++) {
$color = imagecolorallocate ( $image, mt_rand ( 50, 90 ), mt_rand ( 80, 200 ), mt_rand ( 90, 180 ) );
imageline ( $image, mt_rand ( 0, $width - 1 ), mt_rand ( 0, $height - 1 ), mt_rand ( 0, $width - 1 ), mt_rand ( 0, $height - 1 ), $color );
}
}
header ( "content-type:image/gif" );
imagegif ( $image );
imagedestroy ( $image );
}
Main points:
1. If session_start() is not declared before; then it needs to be declared;
2. Fonts can be downloaded to your own defined fonts folder by entering fonts in cmf;
3. $_SESSION [$sess_name] can obtain the verification code entered by the user through $_POST for comparison.
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