function my_autoload($name){
$name = str_replace('\\',DIRECTORY_SEPARATOR,$name);
require $name.'.class.php';
}

spl_autoload_register(__NAMESPACE__.'\\my_autoload');

<?php
namespace Index;
use auto\say;
use auto\mycolor\color;
function my_autoload($name){
$name = str_replace('\\',DIRECTORY_SEPARATOR,$name);
require $name.'.class.php';
}
spl_autoload_register(__NAMESPACE__.'\\my_autoload');
$say = new say();
$say->hello();
$color = new color();
$color->test();

b. auto/say.class.php：

<?php
namespace auto;
class say{
public function hello(){
    echo "hello";
}
}

c. auto/mycolor/color.class.php：

<?php
namespace auto\mycolor;
class color{
public function test(){
    echo "blue";
}
}			本文转自 bilinyee博客，原文链接：      http://blog.51cto.com/12173069/2071302  如需转载请自行联系原作者