开发应用中验证码是少不了的,我们经常会碰以关于被机器注册,那么有了验证码可以有效的防止这类行为,下面我们来看看我提供的这款代码,实例代码如下:
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<?php
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session_start();
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class authnum {
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private $im;
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private $im_width;
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private $im_height;
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private $len;
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private $randnum;
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private $y;
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private $randcolor;
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public $red=238;
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public $green=238;
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public $blue=238;
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public $ext_num_type='';
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public $ext_pixel = false;
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public $ext_line = false;
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public $ext_rand_y= true;
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function __construct ($len=4,$im_width='',$im_height=25) {
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$this->len = $len; $im_width = $len * 15;
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$this->im_width = $im_width;
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$this->im_height= $im_height;
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$this->im = imagecreate($im_width,$im_height);
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}
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function set_bgcolor () {
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imagecolorallocate($this->im,$this->red,$this->green,$this->blue);
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}
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function get_randnum () {
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$an1 = 'abcdefghijklmnopqrstuvwxyz';
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$an2 = 'abcdefghijklmnopqrstuvwxyz';
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$an3 = '0123456789';
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if ($this->ext_num_type == '') $str = $an1.$an2.$an3;
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if ($this->ext_num_type == 1) $str = $an1;
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if ($this->ext_num_type == 2) $str = $an2;
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if ($this->ext_num_type == 3) $str = $an3;
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for ($i = 0; $i < $this->len; $i++) {
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$start = rand(1,strlen($str) - 1);
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$randnum .= substr($str,$start,1);
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}
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$this->randnum = $randnum;
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$_session[an] = $this->randnum;
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}
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function get_y () {
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if ($this->ext_rand_y) $this->y = rand(5, $this->im_height/5);
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else $this->y = $this->im_height / 4 ;
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}
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function get_randcolor () {
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$this->randcolor = imagecolorallocate($this->im,rand(0,100),rand(0,150),rand(0,200));
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}
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function set_ext_pixel () {
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if ($this->ext_pixel) {
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for($i = 0; $i < 100; $i++){
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$this->get_randcolor();
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imagesetpixel($this->im, rand()%100, rand()%100, $this->randcolor);
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}
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}
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}
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function set_ext_line () {
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if ($this->ext_line) {
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for($j = 0; $j < 2; $j++){
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$rand_x = rand(2, $this->im_width);
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$rand_y = rand(2, $this->im_height);
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$rand_x2 = rand(2, $this->im_width);
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$rand_y2 = rand(2, $this->im_height);
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$this->get_randcolor();
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imageline($this->im, $rand_x, $rand_y, $rand_x2, $rand_y2, $this->randcolor);
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}
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}
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}
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function create () {
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$this->set_bgcolor();
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$this->get_randnum ();
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for($i = 0; $i < $this->len; $i++){
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$font = rand(4,6);
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$x = $i/$this->len * $this->im_width + rand(1, $this->len);
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$this->get_y();
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$this->get_randcolor();
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imagestring($this->im, $font, $x, $this->y, substr($this->randnum, $i ,1), $this->randcolor);
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}
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$this->set_ext_line();
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$this->set_ext_pixel();
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header("content-type:image/png");
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imagepng($this->im);
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imagedestroy($this->im);
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}
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}
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$an = new authnum();
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$an->ext_num_type='';
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$an->ext_pixel = true;
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$an->ext_line = false;
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$an->ext_rand_y= true;
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$an->green = 238;
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$an->create();
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?>
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(责任编辑:最模板) |