function writeImage($width, $height, $strLen, $fontSize, $angMax, $font, $penColorRGB, $backColorRGB)
{
$im = Imagecreate($width, $height);
$backColorArray = explode(',', $backColorRGB);
// Get RGB componenets
// from string
$penColorArray = explode(',', $penColorRGB);
$backColor = imagecolorallocate($im, $backColorArray[0], $backColorArray[1], $backColorArray[2]);
// allocate
// color
// for
// background
$penColor = imagecolorallocate($im, $penColorArray[0], $penColorArray[1], $penColorArray[2]);
// allocate
// color
// for
// writing
$x = 20;
// Start writing from $x with initial 20 pixels left blank
$y = $fontSize + 20;
$str = "";
// Declaration just to avoid "undefined variable" warning
for ($i = 0; $i <= $strLen - 1; $i++) {
$chr = getRandChr();
// Generate a random character
$str .= "{$chr}";
// Append to a string, for storing to SESSION
$angle = rand(0, $angMax);
// Set angle between 0 to $angMax
if (rand(0, 1) == 0) {
// Set Positive or Negative angle randomly
$angle = -$angle;
}
ImageTTFText($im, $fontSize, $angle, $x, $y, $penColor, $font, $chr);
$x = $x + 50;
// Increment in x coordinate
}
$_SESSION['CaptchaCode'] = md5($str);
// Assuming session is already
// started, final CAPTCHA string
// is stored in session
header('Content-type: image/jpeg');
// Set header
imagejpeg($im);
// produce jpeg image
imagedestroy($im);
// free-up temporary memory used to store image
}
/**
* @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
}
private function create_do()
{
$this->im = Imagecreate($this->config['width'], $this->config['height']);
//设置背景为白色
Imagecolorallocate($this->im, $this->config['color'][0], $this->config['color'][1], $this->config['color'][2]);
//为此背景加个边框
if ($this->config['boxline'] == True) {
$bordercolor = Imagecolorallocate($this->im, 37, 37, 37);
Imagerectangle($this->im, 0, 0, $this->config['width'] - 1, $this->config['height'] - 1, $bordercolor);
}
//生成验证码
$this->create_str();
$coder = $_SESSION[$this->config['codname']];
//输入文字
$fontcolor = Imagecolorallocate($this->im, 46, 46, 46);
for ($i = 0; $i < $this->config['length']; $i++) {
Imagestring($this->im, 5, $i * 10 + 6, rand(2, 5), $coder[$i], $fontcolor);
}
//加入干扰线
$interfere = $this->config['interfere'];
$interfere = $interfere > 30 ? "30" : $interfere;
if (!empty($interfere) && $interfere > 1) {
for ($i = 1; $i < $interfere; $i++) {
$linecolor = Imagecolorallocate($this->im, rand(0, 255), rand(0, 255), rand(0, 255));
$x = rand(1, $this->config['width']);
$y = rand(1, $this->config['height']);
$x2 = rand($x - 10, $x + 10);
$y2 = rand($y - 10, $y + 10);
Imageline($this->im, $x, $y, $x2, $y2, $linecolor);
}
}
ob_clean();
Header("Pragma:no-cache\r\n");
Header("Cache-Control:no-cache\r\n");
Header("Expires:0\r\n");
Header("Content-type:Image/jpeg\r\n");
Imagejpeg($this->im);
Imagedestroy($this->im);
exit;
}
/**
* 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;");