PHP实现的功能是显示8条基色色带

由于PHP的本色表参数只能支持256,为了能实现显示8色或更多的色带,我使用了参数传递的方法来实现。具体实现的代码如下:1、生成色带图形的程序transition.php?php/**功能:生成色带图形*程序员:wlxz*
日期:2002-00-00*/Header(Content-type: image/Png);$im =
ImageCreate(255,50);$bgcolor = ImageColorAllocate($im, 0, 0, 0);$x =
trim($_GET[‘x’]);$y = trim($_GET[‘y’]);$z =
trim($_GET[‘z’]);for($i=0;$i255;$i++){$fontcol =
ImageColorAllocate($im, $i*$x, $i*$y, $i*$z);ImageLine($im, $i, 0,
$i, 50,
$fontcol);}ImagePng($im);ImageDestroy($im);?2、调用生成多个不同的图形view_color.php?php/**功能:*程序员:向黎*
日期:2002-00-00*/?htmlheadtitle/titlemeta name=Author content=XIANG
Li/headbodytabletrtd!–色带1–input type=image
src=./transition.php?x=0&y=0&z=0/td/trtrtd!–色带2–input type=image
src=./transition.php?x=0&y=0&z=1/td/trtrtd!–色带3–input type=image
src=./transition.php?x=0&y=1&z=0/td/trtrtd!–色带4–input type=image
src=./transition.php?x=0&y=1&z=1/td/trtrtd!–色带5–input type=image
src=./transition.php?x=1&y=0&z=0/td/trtrtd!–色带6–input type=image
src=./transition.php?x=1&y=0&z=1/td/trtrtd!–色带7–input type=image
src=./transition.php?x=1&y=1&z=0/td/trtrtd!–色带8–input type=image
src=./transition.php?x=1&y=1&z=1/td/tr/table/body/html

1、产生一张png的图片
2、为图片设置背景色
3、设置字体颜色和样式
4、产生4位数的随机的验证码
5、把产生的每个字符调整旋转角度和位置画到png图片上
6、加入噪点和干扰线防止注册机器分析原图片来恶意注册
7、输出图片
8、释放图片所占内存
authcode.php文件

代码

 代码如下

<?php
        session_start ();
        header ( ‘Content-type: image/png’ );
        //创建图片
        $im = imagecreate($x=130,$y=45 );
        $bg =
imagecolorallocate($im,rand(50,200),rand(0,155),rand(0,155)); //第一次对
imagecolorallocate() 的调用会给基于调色板的图像填充背景色
        $fontColor = imageColorAllocate ( $im, 255, 255, 255 );  
//字体颜色
        $fontstyle = ‘rock.ttf’;                  
//字体样式,这个可以从c:windowsFonts文件夹下找到,我把它放到和authcode.php文件同一个目录,这里可以替换其他的字体样式
        //产生随机字符
        for($i = 0; $i < 4; $i ++) {
                $randAsciiNumArray         = array
(rand(48,57),rand(65,90));
                $randAsciiNum                 = $randAsciiNumArray
[rand ( 0, 1 )];
                $randStr                         = chr ( $randAsciiNum
);
               
imagettftext($im,30,rand(0,20)-rand(0,25),5+$i*30,rand(30,35),$fontColor,$fontstyle,$randStr);
                $authcode                        .= $randStr;
        }
        $_SESSION[‘authcode’]        =
$randFourStr;//用户和用户输入的验证码做比较
        //干扰线
        for ($i=0;$i<8;$i++){
                $lineColor        =
imagecolorallocate($im,rand(0,255),rand(0,255),rand(0,255));
                imageline ($im,rand(0,$x),0,rand(0,$x),$y,$lineColor);
        }
        //干扰点
        for ($i=0;$i<250;$i++){
                imagesetpixel($im,rand(0,$x),rand(0,$y),$fontColor);
        }
        imagepng($im);
        imagedestroy($im);               
?>

例2

php验证码” alt=”” src=”/notfound.jpg” width=”499″ height=”196″ />

•新建一个PHP文件captcha_code_file.php

 代码如下

//首先开启session
session_start();
//定义前台显示验证码长&宽
$image_width = 120;
$image_height = 40;
$characters_on_image = 6;
$font = ‘./monofont.ttf’;
 
//The characters that can be used in the CAPTCHA code.
//avoid confusing characters (l 1 and i for example)
$possible_letters = ‘23456789bcdfghjkmnpqrstvwxyz’;
$random_dots = 10;
$random_lines = 30;
$captcha_text_color=”0x142864″;
$captcha_noice_color = “0x142864”;
//定义要生成验证码的字符串
$code = ”;
 
$i = 0;
while ($i < $characters_on_image) { 
$code .=
substr($possible_letters,
mt_rand(0, strlen($possible_letters)-1), 1);
$i++;
}
 
$font_size = $image_height * 0.75;
$image = @imagecreate($image_width, $image_height);
 
/* setting the background, text and noise colours here */
$background_color = imagecolorallocate($image, 255, 255, 255);
 
$arr_text_color = hexrgb($captcha_text_color);
$text_color = imagecolorallocate($image, $arr_text_color[‘red’], 
        $arr_text_color[‘green’], $arr_text_color[‘blue’]);
 
$arr_noice_color = hexrgb($captcha_noice_color);
$image_noise_color = imagecolorallocate($image,
$arr_noice_color[‘red’], 
        $arr_noice_color[‘green’], $arr_noice_color[‘blue’]);
 
/* generating the dots randomly in background */
for( $i=0; $i<$random_dots; $i++ ) {
imagefilledellipse($image,
mt_rand(0,$image_width),
 mt_rand(0,$image_height), 2, 3, $image_noise_color);
}
 
/* generating lines randomly in background of image */
澳门新葡亰网站注册,for( $i=0; $i<$random_lines; $i++ ) {
imageline($image, mt_rand(0,$image_width),
mt_rand(0,$image_height),
 mt_rand(0,$image_width), mt_rand(0,$image_height),
$image_noise_color);
}
 
/* create a text box and add 6 letters code in it */
$textbox = imagettfbbox($font_size, 0, $font, $code); 
$x = ($image_width – $textbox[4])/2;
$y = ($image_height – $textbox[5])/2;
imagettftext($image, $font_size, 0, $x, $y, $text_color, $font ,
$code);
 
/* Show captcha image in the page html page */
header(‘Content-Type: image/jpeg’);// defining the image type to be
shown in browser widow
imagejpeg($image);//showing the image
imagedestroy($image);//destroying the image instance
//设置session,做验证
$_SESSION[‘6_letters_code’] = $code;
 
function hexrgb ($hexstr)
{
  $int = hexdec($hexstr);
 
  return array(“red” => 0xFF & ($int >> 0x10),
               “green” => 0xFF & ($int >> 0x8),
               “blue” => 0xFF & $int);
}

显示验证码页面index.php

<?php
session_start();
if(isset($_REQUEST[‘Submit’])){
    // code for check server side validation
    if(empty($_SESSION[‘6_letters_code’] ) ||
        strcasecmp($_SESSION[‘6_letters_code’],
$_POST[‘6_letters_code’]) != 0)
    {  
        $msg=”您输入的验证码有误,请重新输入!”;
    }else{
        echo “您输入的是正确的!”;
        // Captcha verification is Correct. Final Code Execute here!
    }
}    
 ?>
 
<style type=”text/css”>
.table{
    font-family:Arial, Helvetica, sans-serif;
    font-size:12px;
    color:#333;
    background-color:#E4E4E4;    
}
.table td{
    <a href=” Money point</a> 
background-color:#F8F8F8;     
}
</style>
 
<form action=”” method=”post” name=”form1″ id=”form1″ >
  <table width=”400″ border=”0″ align=”center” cellpadding=”5″
cellspacing=”1″>
<?php if(isset($msg)){?>
    <tr>
      <td colspan=”2″ align=”center” valign=”top”><?php echo
$msg;?></td>
    </tr>
<?php } ?> 
    <tr>
      <td align=”right” valign=”top”> 验证码Demo:</td>
      <td><img src=”captcha_code_file.php?rand=<?php echo
rand(0,20);?>” id=’captchaimg’  onclick=”refreshCaptcha();”
><br>
        <label for=’message’>请输入验证码:</label>
        <br>
        <input id=”6_letters_code” name=”6_letters_code”
type=”text”>
        <br>
        如果看不到,请 <a
href=’javascript:
refreshCaptcha();’>点我</a> 刷新一下!
        </p></td>
    </tr>
    <tr>
      <td>&nbsp;</td>
      <td><input name=”Submit” type=”submit” onclick=”return
validate();” value=”Submit”></td>
    </tr>
  </table>
</form>
<script type=’text/javascript’>
//定义的刷新请求
function refreshCaptcha()
{
    var img = document.images[‘captchaimg’];
    img.src =
img.src.substring(0,img.src.lastIndexOf(“?”))+”?rand=”+Math.random()*1000;
}
</script>

例3

带有雪花背景的验证码