在这部分做的是一个后台的用户登录,也就是管理员的登录。
主要有以下几块:
验证码的制作,
对管理员信息的增删改查,
对cooki的操作,
分页操作。
一、验证码是怎么制作呢?
我们是使用的GD库制作验证码的有以下几步:
1、创建一个画布
2、填充画布
3、生成随机字符串
4、将字符串保存到session中
5、添加字体
6、将字符串写到画布上
通过以上六步就把验证码做好了,但是要增加一些干扰元素,通过函数取增加一些点和线。
随机字符串生成函数:
function buildRandomString($type=1,$length=4){
if ($type == 1) {
$chars = join ( "", range ( 0, 9 ) );
} elseif ($type == 2) {
$chars = join ( "", array_merge ( range ( "a", "z" ), range ( "A", "Z" ) ) );
} elseif ($type == 3) {
$chars = join ( "", array_merge ( range ( "a", "z" ), range ( "A", "Z" ), range ( 0, 9 ) ) );
}
if ($length > strlen ( $chars )) {
exit ( "错误" );
}
$chars = str_shuffle ( $chars );
return substr ( $chars, 0, $length );
}
验证码生成函数:
function verifyImage($type = 1, $length = 4, $pixel = 0, $line = 0,$sess_name = "verify"){
//��������
$width = 80;
$height = 28;
$image = imagecreatetruecolor($width, $height);
$white = imagecolorallocate($image, 255, 255, 255);
$black = imagecolorallocate($image, 0, 0, 0);
imagefilledrectangle($image, 1, 1, $width - 2, $height - 2, $white);
$chars = buildRandomString($type, $length);
$_SESSION[$sess_name] = $chars;
$fontfiles = array(
"MSYH.TTF",
"MSYHBD.TTF",
"SIMFANG.TTF",
"SIMHEI.TTF",
"SIMKAI.TTF",
"SIMSUN.TTC"
);
for ($i = 0; $i < $length; $i ++) {
$size = mt_rand(14, 18);
$angle = mt_rand(- 15, 15);
$x = 5 + $i * $size;
$y = mt_rand(20, 26);
$fontfile = "../fonts/" . $fontfiles[mt_rand(0, count($fontfiles) - 1)];
$color = imagecolorallocate($image, mt_rand(50, 90), mt_rand(80, 200), mt_rand(90, 180));
$text = substr($chars, $i, 1);
imagettftext($image, $size, $angle, $x, $y, $color, $fontfile, $text);
}
//添加干扰元素
if ($pixel) {
for ($i = 0; $i < 50; $i ++) {
imagesetpixel($image, mt_rand(0, $width - 1), mt_rand(0, $height - 1), $black);
}
}
//添加干扰元素
if ($line) { for ($i = 0; $i < $line; $i ++) { $color = imagecolorallocate($image, mt_rand(50, 90), mt_rand(80, 200), mt_rand(90, 180)); imageline($image, mt_rand(0, $width - 1), mt_rand(0, $height - 1), mt_rand(0, $width - 1), mt_rand(0, $height - 1), $color); } } header("content-type:image/gif"); imagegif($image); imagedestroy($image);}
就是这么简单,需要时候直接调用就可以了。