php生成图片验证码

2024-09-04 11:44:28

字体：大中小

来源：转载

供稿：网友

首先,有一个在php.ini看看gd库是不是开启的,下一步,我们会考虑每一个细节的图像生成步骤.

php生成图片验证码实例代码如下:

<?php

//Send a generated image to the browser

create_image();

exit();

function create_image()

{

    //Let's generate a totally random string using md5

    $md5 = md5(rand(0,999));

    //We don't need a 32 character long string so we trim it down to 5

    $pass = substr($md5, 10, 5);

    //Set the image width and height

    $width = 100;

    $height = 20;

    //Create the image resource

    $image = ImageCreate($width, $height);

    //We are making three colors, white, black and gray

    $white = ImageColorAllocate($image, 255, 255, 255);

    $black = ImageColorAllocate($image, 0, 0, 0);

    $grey = ImageColorAllocate($image, 204, 204, 204);

    //Make the background black

    ImageFill($image, 0, 0, $black);

    //Add randomly generated string in white to the image

    ImageString($image, 3, 30, 3, $pass, $white);

    //Throw in some lines to make it a little bit harder for any bots to

break

    ImageRectangle($image,0,0,$width-1,$height-1,$grey);

    imageline($image, 0, $height/2, $width, $height/2, $grey);

    imageline($image, $width/2, 0, $width/2, $height, $grey);

    //Tell the browser what kind of file is come in

    header("Content-Type: image/jpeg");

//开源代码Vevb.com

    //Output the newly created image in jpeg format

    ImageJpeg($image);



    //Free up resources

    ImageDestroy($image);

}

?>