超强php验证码升级版

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<?php
function getCode($length = 32, $mode = 0) {
 switch ($mode) {
 case '1' :
 $str = '123456789';
 break;
 case '2' :
 $str = 'abcdefghijklmnopqrstuvwxyz';
 break;
 case '3' :
 $str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
 break;
 case '4' :
 $str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
 break;
 case '5' :
 $str = 'ABCDEFGHIJKLMNPQRSTUVWXYZ123456789';
 break;
 case '6' :
 $str = 'abcdefghijklmnopqrstuvwxyz1234567890';
 break;
 case '7' ://中文验证码
 break;
 default :
 $str = 'ABCDEFGHIJKLMNPQRSTUVWXYZabcdefghijkmnpqrstuvwxyz23456789';
 break;
 }
 $result = '';
 for($i = 0; $i < $length; $i ++) {
 if ($mode == 7) {
 $str [$i] = chr ( mt_rand ( 176, 215 ) ) . chr ( mt_rand ( 161, 249 ) );
 $str [$i] = iconv ( "GB2312", "UTF-8", $str [$i] ); //imagettftext是utf-8的,所以先转换下
 $result .= $str [$i];
 } else {
 $l = strlen ( $str ) - 1;
 $num = mt_rand ( 0, $l );
 $result .= $str [$num];
 }
 }
 return $result;
}
//建立验证图片
function createAuthNumImg($randStr, $fontName, $imgW = 100, $imgH = 40) {
 header ( "content-type: image/png" );
 $image = imagecreate ( $imgW, $imgH );
 $fontSize = mt_rand(17,20);//字号
 //$green = imagecolorallocate($image,0x6b,0xc1,0x46);
 $gray = imagecolorallocate ( $image, 255, 255, 255 ); //灰色
 $red  = imagecolorallocate ( $image, 255, 102, 204 );//粉色
 $blue = imagecolorallocate($image,0x53,0x68,0xbd);
 $colors = array($red, $gray, $blue);
 $color_b = imagecolorallocate ( $image, 0, 0, 0 ); //黑色
 $color_d = imagecolorallocate ( $image,98,178, 28 ); //绿色
 $color_e = imagecolorallocate ( $image,38,98, 223 ); //蓝色
 $color_c = imagecolorallocate ( $image,255,0, 0 ); //红色
 $color_f = imagecolorallocate ( $image,128,0, 255 ); //紫色
 $color_g = imagecolorallocate ( $image,0,128, 128 ); //
 $color = array($color_b, $color_c, $color_d,$color_e);
 shuffle($color);
 $colorrnd=imagecolorallocate ( $image,mt_rand(0,255),mt_rand(0,255), mt_rand(0,255) );
 for($i = 0; $i < 1000; $i ++) { //绘背景干扰点
 //imagesetpixel ( $image, mt_rand ( 0, $imgW ), mt_rand ( 0, $imgH ), $colors[rand(0,count($colors)-1)]);
 }
 imagerectangle ( $image, 0, 0, $imgW - 1, $imgH - 1, $color_b );//绘制边框
 $str1=substr($randStr,0,1);
 $str2=substr($randStr,1,1);
 $str3=substr($randStr,2,1);
 $str4=substr($randStr,3,1);
 $range=mt_rand(-20,20);
 //imagettftext ( $image, $fontSize, 5, 3, 25, $color_b, $fontName, $randStr);///将验证字符绘入图片 字符旋转
 for($i=1;$i<=4;$i++) {
 $p=$i-1;
 $str=$randStr["$p"];
 //imagettftext ( $image, mt_rand(17,20), mt_rand(-20,20), $i*12, mt_rand(20,25), $color[mt_rand(0,count($color)-1)], $fontName, $str);///将验证字符绘入图片 字符旋转
 imagettftext ( $image, mt_rand(17,20), mt_rand(-20,20), $i*12, mt_rand(20,25), $color[$i-1], $fontName, $str);///将验证字符绘入图片 字符旋转
 }
 //imagettftext ( $image, mt_rand(17,20), mt_rand(-20,20), mt_rand(2,5), mt_rand(20,25), $color_b, $fontName, $str1);///将验证字符绘入图片 字符旋转
 //imagettftext ( $image, mt_rand(17,20), mt_rand(-20,20), mt_rand(16,18), mt_rand(20,25), $color_c, $fontName, $str2);///将验证字符绘入图片 字符旋转
 //imagettftext ( $image, mt_rand(17,20), mt_rand(-20,20), mt_rand(28,30), mt_rand(20,25), $color_d, $fontName, $str3);///将验证字符绘入图片 字符旋转
 //imagettftext ( $image, mt_rand(17,20), mt_rand(-20,20), mt_rand(36,38), mt_rand(20,25), $color_e, $fontName, $str4);///将验证字符绘入图片 字符旋转
 for($i=0; $i<4; $i++){ //绘背景干扰线
 //imageline($image, mt_rand(0,5), mt_rand(6,18), mt_rand(65,$imgW), mt_rand(6,$imgH), $colorrnd);//一条干扰线
 $h=30;
 $h1=rand(-5,5);
 $h2=rand(-1,1);
 $w2=rand(10,15);
 $h3=rand(4,6);
 $w=75;
 for($i=-$w/2;$i<$w/2;$i=$i+0.1)
 {
 $y=$h/$h3*sin($i/$w2)+$h/2+$h1;
 imagesetpixel($image,$i+$w/2,$y,$color[$p]);
 $h2!=0?imagesetpixel($image,$i+$w/2,$y+$h2,$color[$p]):null;
 }
 }
 imagepng ( $image );
 imagedestroy ( $image );
}
session_start ();
$verifyCode = GetCode ( 4 );
$_SESSION ['VERIFY_CODE'] = $verifyCode ;
createAuthNumImg ( $verifyCode, "font.ttf", 75, 30); //字体存放路径,如果你没有文件就去C:\WINDOWS\Fonts文件中找一个吧。
/** 问答模式
$a=GetCode(2,1);
$b=GetCode(1,1);
$passPort = $a."+".$b."=?";
$verifyCode = $a+$b;
$_SESSION ['VERIFY_CODE'] = $verifyCode ;
createAuthNumImg ( $passPort, "font.ttf", 75, 30);
*/
?>