$navy = imagecolorallocate($image, 0x00, 0x00, 0x80);
$darknavy = imagecolorallocate($image, 0x00, 0x00, 0x50);
$red = imagecolorallocate($image, 0xFF, 0x00, 0x00);
$darkred = imagecolorallocate($image, 0x90, 0x00, 0x00);
imagefill($image,0,0,$white);
// make the 3D effect
for ($i = $height /2 +20; $i > $height /2; $i--) {
imagefilledarc($image, $width/2, $i, $width/2, $height /2, 0, 45, $darknavy, IMG_ARC_PIE);
imagefilledarc($image, $width/2, $i, $width/2, $height /2, 45, 75 , $darkgray, IMG_ARC_PIE);
imagefilledarc($image, $width/2, $i, $width/2, $height /2, 75, 360 , $darkred, IMG_ARC_PIE);
}
imagefilledarc($image, $width/2, $height /2, $width/2, $height /2, 0, 45, $navy, IMG_ARC_PIE);
imagefilledarc($image, $width/2, $height /2, $width/2, $height /2, 45, 75 , $gray, IMG_ARC_PIE);
imagefilledarc($image, $width/2, $height /2, $width/2, $height /2, 75, 360 , $red, IMG_ARC_PIE);
// flush image
header('Content-type: image/png');
imagepng($image);
imagedestroy($image);
/*
//发送对象至文件
$filename="ex1.png";
imagepng($image,$filename);
*/
?>
输出:
演示:http://www.phzzy.org/temp/5do8/ex3.php
例四:简单的验证码
PHP创建验证码非常容易,容易的要死,简单的思路是这样的:
随机种子生成,提取随机字符,相连打印到图形,输出.,为了防止色盲,可以随机提取颜色,也可以自定义颜色,下面看看:
<?php
session_start();
$width=65;
$height=20;
$sourcestrings="0123456789aqwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM";
$image=imagecreate($width,$height);
$colorarrs=array(
imagecolorallocate($image,255,255,255),//white
imagecolorallocate($image,0 ,0 , 0)//black
);
unset($sessionval);
imagesetthickness($image,3);
//随机得到字符串个数
$strsize=rand(3,5);
imagefill($image,0,0,$colorarrs[0]);
//一个个的写字符串到图片
for($i=0;$i<$strsize;$i++){
$i_temp=rand(1,62);
$sessionval .=$sourcestrings[$i_temp];
$fontcolor=imagecolorallocate($image,rand(0,255),rand(0,255),rand(0,255));
$y_i = $height/2 + $font_size /3 ;
imagechar($image,5, 1+ $i * $width /$strsize,5,$sourcestrings[$i_temp],$fontcolor);
}
//写入session,以后验证用
unset($_SESSION['cjjer']);
$_SESSION['cjjer'] = $sessionval;
//添加杂点
for($i=0;$i<$width /$height *2;$i++)
{ $i_x=rand(0,$width);
$i_y=rand(0,$height);
$pixelcolor=imagecolorallocate($image,rand(0,255),rand(0,255),rand(0,255));
imagesetpixel($image,$i_x,$i_y,$pixelcolor);
}
header('content-type:image/png');
imagepng($image);
imagedestroy($image);
?>
生成的样式演示:
在线演示:http://www.phzzy.org/temp/5do8/ex4_login.php
有个很明显的问题就是生成的图片不够艳丽,从而很多的用户看起来不清楚,这样吧,我们自己设定几个比较艳丽的颜色然后输出,扩展colorarrs数组:
