public function render($key = '')
{
// 图片宽(px)
$this->imageW || ($this->imageW = $this->codeLen * $this->fontSize + $this->codeLen * $this->fontSize / 2);
// 图片高(px)
$this->imageH || ($this->imageH = $this->fontSize * 1.5);
// 建立一幅 $this->imageW x $this->imageH 的图像
$this->_image = imagecreate($this->imageW, $this->imageH);
// 设置背景
imagecolorallocate($this->_image, $this->bg[0], $this->bg[1], $this->bg[2]);
// 验证码字体随机颜色
$this->_color = imagecolorallocate($this->_image, mt_rand(1, 150), mt_rand(1, 150), mt_rand(1, 150));
// 验证码使用随机字体
$ttfPath = dirname(__FILE__) . '/captcha/' . ($this->useZh ? 'zhttfs' : 'ttfs') . '/';
$this->fontttf = $ttfPath . $this->fontttf;
if ($this->useNoise) {
// 绘杂点
$this->_writeNoise();
}
if ($this->useCurve) {
// 绘干扰线
$this->_writeCurve();
}
// 绘验证码
$code = array();
// 验证码
$codeNX = -20;
// 验证码第N个字符的左边距
if ($this->useZh) {
// 中文验证码
for ($i = 0; $i < $this->codeLen; $i++) {
$code[$i] = iconv_substr($this->zhSet, floor(mt_rand(0, mb_strlen($this->zhSet, 'utf-8') - 1)), 1, 'utf-8');
imagettftext($this->_image, $this->fontSize, mt_rand(-40, 40), $this->fontSize * ($i + 1) * 1.5, $this->fontSize + mt_rand(10, 20), $this->_color, $this->fontttf, $code[$i]);
}
} else {
for ($i = 0; $i < $this->codeLen; $i++) {
$code[$i] = $this->codeSet[mt_rand(0, strlen($this->codeSet) - 1)];
$codeNX += mt_rand($this->fontSize * 1.2, $this->fontSize * 1.4);
//echo $codeNX.'<br/>';
imagettftext($this->_image, $this->fontSize, mt_rand(-30, 30), $codeNX, $this->fontSize * 1.3, $this->_color, $this->fontttf, $code[$i]);
}
}
// 保存验证码
$key = $this->authcode($this->seKey) . $key;
$code = $this->authcode(strtoupper(implode('', $code)));
$secode = array();
$secode['verify_code'] = $code;
// 把校验码保存到session
$secode['verify_time'] = $this->_nowTime->timeStamp;
// 验证码创建时间
Util_Session::set($key, $secode);
header('Cache-Control: private, max-age=0, no-store, no-cache, must-revalidate');
header('Cache-Control: post-check=0, pre-check=0', false);
header('Pragma: no-cache');
header("content-type: image/png");
// 输出图像
imagepng($this->_image);
imagedestroy($this->_image);
}
