PHP校验码生成--备忘
<?php session_start();//保存生成值,以与用户输入比较 //------------------------------------- $img_w = 80;// 设置图片宽 $img_h = 20;// 设置图片高 $pixel_num = 200;//点越多干扰越大 $is_set_line = true;// 启用干扰线 $pixel_mode = 2;// 干扰点模式,1,同色;2,杂色 //------------------------------------- // 随机数产生器 function make_seed() { list($usec, $sec) = explode(' ', microtime()); return (float) $sec + ((float) $usec * 100000); } mt_srand(make_seed());//4.2.0以下版本适用 $authnum = mt_rand(100, 99999); // 加入session $_SESSION['verifycode']=$authnum; //echo $authnum; //生成验证码图片 Header("Content-type: image/PNG"); $im = imagecreatetruecolor($img_w, $img_h); $bg_color = ImageColorAllocate($im, mt_rand(250,255),mt_rand(250,255),mt_rand(250,255)); // 绘制背景 imagefill($im,0,0,$bg_color); $total_width = 0; $word_info = array(); // 循环,获取文字信息 $word_length = strlen($authnum); for($ii=0; $ii<$word_length; $ii++) { $word_space = mt_rand(1,5); $font = rand(3,5); mt_rand(1,9)%2 == 0?$top = 1:$top = 3; $word_info[$ii]['char'] = substr($authnum,$ii,1); $word_info[$ii]['font'] = $font; $word_info[$ii]['offset'] = $top; if($ii == 0) { $word_info[$ii]['width'] = 0; } $word_info[$ii]['width'] = imageFontWidth($font)+$word_space; $word_info[$ii]['height'] = imageFontHeight($font); $word_info[$ii]['color'] = imageColorAllocate($im, mt_rand(0,50),mt_rand(0,150),mt_rand(0,200)); // 文字总宽度 $total_width += $word_info[$ii]['width']; // 取第一个字体的高度 if($ii == 0) { $total_height = imagefontHeight($font); } } // 计算偏移 $offset_x = floor(($img_w - $total_width)/2); $offset_y = floor(($img_h - $total_height)/2); // 填充验证码 $wid = 0; $i = 0; foreach($word_info as $key=>$val) { if($i>0) { $wid += $val['width']; } imagestring($im, $val['font'], $offset_x + $wid, $val['offset'] + $offset_y, $val['char'], $val['color']); $i++; } switch($pixel_mode) { case 1: $pixel_color = ImageColorAllocate($im, mt_rand(50,255), mt_rand(50,255), mt_rand(50,255)); // 干扰象素 for($i=0;$i