PHP version of the verification code program _ PHP Tutorial

PHP verification code program .? Php generates the verification code Image Header (Content-type: imagePNG); srand (double) microtime () * 1000000); play the next seed to generate random numbers to facilitate the use of the following random number generation // Generate a verification code Image
Header ("Content-type: image/PNG ");
Srand (double) microtime () * 1000000); // play the next seed that generates random numbers to facilitate the use of the following random number generation

Session_start (); // Save the random number to the session.
$ _ SESSION ['authnum'] = "";
$ Im = imagecreate (); // specify the image background size.

$ Black = ImageColorAllocate ($ im, 0, 0); // you can specify three colors.
$ White = ImageColorAllocate ($ im, 255,255,255 );
$ Gray = ImageColorAllocate ($ im, 200,200,200 );

Imagefill ($ im, $ gray); // use the area filling method, set)

While ($ authnum = rand () 0000) <10000 );
// Print the four-digit integer verification code into the image
$ _ SESSION ['authnum'] = $ authnum;
Imagestring ($ im, 5, 10, 3, $ authnum, $ black );
// Use the col color to draw the string s to the x and y coordinates of the image (0 and 0 in the upper left corner of the image ).
// If the font is 1, 2, 3, 4, or 5, the built-in font is used.

For ($ I = 0; $ I <200; $ I) // add interference pixels
{
$ Randcolor = ImageColorallocate ($ im, rand (0,255), rand (0,255), rand (0,255 ));
Imagesetpixel ($ im, rand () p, rand () 0, $ randcolor );
}


ImagePNG ($ im );
ImageDestroy ($ im );
?>

Http://www.bkjia.com/PHPjc/631989.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/631989.htmlTechArticle? Php // Generate the verification code image Header (Content-type: image/PNG); srand (double) microtime () * 1000000); // play the next seed that generates random numbers, to facilitate the use of the following random number generation...