Php image verification code generation program code

Session_start ();
Class authnum {
// Image object, width, height, and verification code length
Private $ im;
Private $ im_width;
Private $ im_height;
Private $ len;
// Random string, Y axis coordinate value, and random color
Private $ randnum;
Private $ y;
Private $ randcolor;
// The red, green, and blue background color. The default value is light gray.
Public $ red= 238;
Public $ green = 238;
Public $ blue = 238;
/**
* Optional settings: verification code type, interference point, interference line, and y-axis random
* If it is set to false, this parameter is disabled.
**/
// The default value is a combination of upper and lower case numbers. The value 1 2 3 indicates lower case, upper case, and number type respectively.
Public $ ext_num_type = '';
Public $ ext_pixel = false; // interference point
Public $ ext_line = false; // interference line
Public $ ext_rand_y = true; // random Y axis
Function _ construct ($ len = 4, $ im_width = '', $ im_height = 25 ){
// The verification code length, image width, and height are required for class instantiation.
$ This-> len = $ len; $ im_width = $ len * 15;
$ This-> im_width = $ im_width;
$ This-> im_height = $ im_height;
$ This-> im = imagecreate ($ im_width, $ im_height );
 }
// Set the background color of the image. The default value is light gray.
Function set_bgcolor (){
Imagecolorallocate ($ this-> im, $ this-> red, $ this-> green, $ this-> blue );
 }
// Obtain random digits
Function get_randnum (){
$ An1 = 'abcdefghijklmnopqrstuvwxy ';
$ An2 = 'abcdefghijklmnopqrstuvwxy ';
$ An3 = '20140901 ';
If ($ this-> ext_num_type = '') $ str = $ an1. $ an2. $ an3;
If ($ this-> ext_num_type = 1) $ str = $ an1;
If ($ this-> ext_num_type = 2) $ str = $ an2;
If ($ this-> ext_num_type = 3) $ str = $ an3;
For ($ I = 0; $ I <$ this-> len; $ I ++ ){
$ Start = rand (1, strlen ($ str)-1 );
$ Randnum. = substr ($ str, $ start, 1 );
  }
$ This-> randnum = $ randnum;
$ _ Session [an] = $ this-> randnum;
 }
// Obtain the verification code Image Y axis
Function get_y (){
If ($ this-> ext_rand_y) $ this-> y = rand (5, $ this-> im_height/5 );
Else $ this-> y = $ this-> im_height/4;
 }
// Obtain random colors
Function get_randcolor (){
$ This-> randcolor = imagecolorallocate ($ this-> im, rand (0,100), rand (0,150), rand (0,200 ));
 }
// Add interference points
Function set_ext_pixel (){
If ($ this-> ext_pixel ){
For ($ I = 0; I I <100; $ I ++ ){
$ This-> get_randcolor ();
Imagesetpixel ($ this-> im, rand () % 100, rand () % 100, $ this-> randcolor );
   }
  }
 }
// Add interference lines
Function set_ext_line (){
If ($ this-> ext_line ){
For ($ j = 0; $ j <2; $ j ++ ){
$ Rand_x = rand (2, $ this-> im_width );
$ Rand_y = rand (2, $ this-> im_height );
$ Rand_x2 = rand (2, $ this-> im_width );
$ Rand_y2 = rand (2, $ this-> im_height );
$ This-> get_randcolor ();
Imageline ($ this-> im, $ rand_x, $ rand_y, $ rand_x2, $ rand_y2, $ this-> randcolor );
   }
  }
 }
/** Create a verification code Image:
* Create a canvas (_ construct function)
* Set the canvas background ($ this-> set_bgcolor ();)
* Obtain a random string ($ this-> get_randnum ();)
* Writing text to an image (imagestring function)
* Add interference points/lines ($ this-> set_ext_line (); $ this-> set_ext_pixel ();)
* Output image
**/
Function create (){
$ This-> set_bgcolor ();
$ This-> get_randnum ();
For ($ I = 0; $ I <$ this-> len; $ I ++ ){
$ Font = rand (4, 6 );
$ X = $ I/$ this-> len * $ this-> im_width + rand (1, $ this-> len );
$ This-> get_y ();
$ This-> get_randcolor ();
Imagestring ($ this-> im, $ font, $ x, $ this-> y, substr ($ this-> randnum, $ I, 1 ), $ this-> randcolor );
  }
$ This-> set_ext_line ();
$ This-> set_ext_pixel ();
Header ("content-type: image/png ");
Imagepng ($ this-> im );
Imagedestroy ($ this-> im); // release image resources
 }

} // End class
/** Methods for using the verification code class:
* $ An = new authnum (verification code length, image width, and image height );
* If the parameter is not included in the instantiation, the default value is a four-digit 60*25-size regular verification code image.
* Check the verification code on the form page. Compare whether $ _ session [an] is equal to $ _ post [verification code text box id].
* Optional configuration:
* 1. Verification code type: $ an-> ext_num_type = 1. The value 1 indicates lower case, 2 indicates upper case, and 3 Indicates number.
* 2. Interference point: $ an-> ext_pixel = false; a value of false indicates no interference point is added.
* 3. Interference line: $ an-> ext_line = false; false indicates no interference line is added.
* 4. Y-axis random: $ an-> ext_rand_y = false; if the value is false, y-axis random is not supported.
* 5. Image background: change the value of the three member variables $ red $ green $ blue.
**/
$ An = new authnum ();
$ An-> ext_num_type = '';
$ An-> ext_pixel = true; // interference point
$ An-> ext_line = false; // interference line
$ An-> ext_rand_y = true; // random Y axis
$ An-> green = 238;
$ An-> create ();
?>

Let's take a look at a verification code call instance.

Demo:

Reference content is as follows:
<! Doctype html public "-// w3c // dtd xhtml 1.0 transitional // en" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<Html xmlns = "http://www.w3.org/1999/xhtml">
<Head>
<Meta http-equiv = "content-type" content = "text/html; charset = gb2312"/>
<Title> hi.baidu.com/ji_haiyang </title>
</Head>

<Body>
<Form action = "demo1.php tutorial" method = "post" name = "form1">
<Input name = "test" type = "text" value = "1234"/>
<Div onclick = 'This. innerhtml = " </img> "'>
</img>
</Div>
<Input name = "test2" type = "text" value = "1"/>
<Input name = "submit" type = "submit" value = "submit"/>
</Form>

</Body>
</Html>

 

Example demo1:

<? Php

Session_start ();
$ Test = $ _ post ['test'];
$ Test = trim ($ test );
$ Submit = $ _ post ['submit '];
If ($ test ==$ _ session ['vcode']) {
Echo 'True, correct verification code ';
} Else {
Echo 'false, incorrect verification code ';
}

?>
 

Call the file vcode. php: the reference content is as follows:
<? Php
/**
* The default verification code session is vcode. That is, $ _ session ['vcode'];
* Do not conflict the variable name with the session when giving the variable value.
* Note: it is case-insensitive during verification.
*/
Include ("inc_vcode_class.php ");
$ V = new vcode;
// $ Config ['width'] = 50; // verification code width
// $ Config ['height'] = 20; // high verification code
// $ Config ['vcode'] = "vcode"; // The session used to check the verification code
// $ Config ['type'] = "default"; // verification code display type default: uppercase letters, string: lowercase letters, int: number php programmer site
// $ Config ['length'] = 4; // verification code length
// $ Config ['interfere'] = 10; // interference line intensity, ranging from 1 to 30, 0, or no interference line available
// $ V-> init ($ config); // Configure
$ V-> create ();
?>

Verification code class inc_vcode_class.php: www ~ Phperz ~ Com:
<? Php
/**
* Verification code
* Note: gd database support is required.
*/
Session_start ();
Class vcode {
Private $ config;
Private $ im;
Private $ str;

Function _ construct (){
$ This-> config ['width'] = 50;
$ This-> config ['height'] = 20;
$ This-> config ['vcode'] = "vcode ";
$ This-> config ['type'] = "default ";
$ This-> config ['length'] = 4;
$ This-> config ['interfere'] = 10;

$ This-> str ['default'] = "abcdefghijklmnopqrstuvwxyz ";
$ This-> str ['string'] = "abcdefghijklmnopqrstuvwxyz ";
$ This-> str ['int'] = "0123456789 ";
}

// Configure
Public function init ($ config = array ()){
If (! Empty ($ config) & is_array ($ config )){
Foreach ($ config as $ key => $ value ){
$ This-> config [$ key] = $ value;
}
}
}

// Output the verification code
Public function create (){
If (! Function_exists ("imagecreate ")){
Return false;
}
$ This-> create_do ();
}

// Create
Private function create_do (){
$ This-> im = imagecreate ($ this-> config ['width'], $ this-> config ['height']); php programmer's house
// Set the background to White
Imagecolorallocate ($ this-> im, 255,255,255 );

// Add a border for the background
$ Bordercolor = imagecolorallocate ($ this-> im, 37,37, 37 );
Imagerectangle ($ this-> im, 0, 0, $ this-> config ['width']-1, $ this-> config ['height']-1, $ bordercolor );

// Generate the verification code
$ This-> create_str ();
$ Vcode = $ _ session [$ this-> config ['vcode'];

// Input text
$ Fontcolor = imagecolorallocate ($ this-> im, 6,46, 46 );
For ($ I = 0; $ I <$ this-> config ['length']; $ I ++ ){
Imagestring ($ this-> im, 5, $ I * 10 + 6, rand (2, 5), $ vcode [$ I], $ fontcolor );
}

// Add interference lines
$ Interfere = $ this-> config ['interfere'];
$ Interfere = $ interfere> 30? "30": $ interfere; php programmer site
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 );
}
}

Header ("pragma: no-cachern ");
Header ("cache-control: no-cachern ");
Header ("expires: 0rn ");
Header ("content-type: image/policrn ");
Imagejpeg ($ this-> im );
Imagedestroy ($ this-> im );
Exit;
}

// Obtain the verification code
Private function create_str (){
If ($ this-> config ['type'] = "int "){
For ($ I = 1; $ I <= $ this-> config ['length']; $ I ++ ){
$ Vcode. = rand (0, 9 );
}
$ _ Session [$ this-> config ['vcode'] = $ vcode;
Return true;
}
$ Len = strlen ($ this-> str [$ this-> config ['type']);
If (! $ Len ){
$ This-> config ['type'] = "default ";
$ This-> create_str ();
}
For ($ I = 1; $ I <= $ this-> config ['length']; $ I ++ ){
$ Offset = rand (0, $ len-1 );
$ Vcode. = substr ($ this-> str [$ this-> config ['type'], $ offset, 1 );
}
$ _ Session [$ this-> config ['vcode'] = $ vcode;
Return true;
}
}