/**
* @throws Exception
* 生成验证码 ， 存放到token相对应的session里面
*/
public function createCaptcha()
{
$token = $_COOKIE["token"];
if (empty($token)) {
throw new Exception("无法生产验证码，请稍后在试");
}
$string = "abcdefghijklmnopqrstuvwxyz0123456789";
$str = "";
for ($i = 0; $i < 4; $i++) {
$pos = rand(0, 35);
$str .= $string[$pos];
}
$this->load->library('session');
$flag = $this->session->set_userdata($token . "_captcha", $str);
$img_handle = Imagecreate(80, 20);
//图片大小80X20
$back_color = ImageColorAllocate($img_handle, 255, 255, 255);
//背景颜色（白色）
$txt_color = ImageColorAllocate($img_handle, 0, 0, 0);
//文本颜色（黑色）
//加入干扰线
for ($i = 0; $i < 3; $i++) {
$line = ImageColorAllocate($img_handle, rand(0, 255), rand(0, 255), rand(0, 255));
Imageline($img_handle, rand(0, 15), rand(0, 15), rand(100, 150), rand(10, 50), $line);
}
//加入干扰象素
for ($i = 0; $i < 200; $i++) {
$randcolor = ImageColorallocate($img_handle, rand(0, 255), rand(0, 255), rand(0, 255));
Imagesetpixel($img_handle, rand() % 100, rand() % 50, $randcolor);
}
Imagefill($img_handle, 0, 0, $back_color);
//填充图片背景色
ImageString($img_handle, 28, 20, 0, $str, $txt_color);
//水平填充一行字符串
ob_clean();
// ob_clean()清空输出缓存区
header("Content-type: image/png");
//生成验证码图片
Imagepng($img_handle);
//显示图片
}
/**
* Created by PhpStorm.
* User: zhuangshaoxiong
* Date: 2015/12/3
* Time: 20:19
*/
$string = "abcdefghijklmnopqrstuvwxyz0123456789";
$str = "";
for ($i = 0; $i < 4; $i++) {
$pos = rand(0, 35);
$str .= $string[$pos];
}
session_start();
$_SESSION['checknode'] = $str;
$img_handle = Imagecreate(100, 20);
$back_color = ImageColorAllocate($img_handle, 255, 255, 255);
$txt_color = ImageColorAllocate($img_handle, 0, 0, 0);
echo ddddd;
for ($i = 0; $i < 3; $i++) {
$line = ImageColorAllocate($img_handle, rand(0, 255), rand(0, 255), rand(0, 255));
Imageline($img_handle, rand(0, 15), rand(0, 15), rand(100, 150), rand(10, 50), $line);
}
for ($i = 0; $i < 200; $i++) {
$randcolor = ImageColorallocate($img_handle, rand(0, 255), rand(0, 255), rand(0, 255));
Imagesetpixel($img_handle, rand() % 100, rand() % 50, $randcolor);
}
Imagefill($img_handle, 0, 0, $back_color);
ImageString($img_handle, 28, 10, 0, $str, $txt_color);
ob_clean();
header("Content-Type: image/png;");
Imagepng($img_handle);
