针对a 去掉url中index.php
.htaccess内容如下：
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f #这个重要，保证css,js正常加载
RewriteCond $1 !^(index\.php|images|robots\.txt)
RewriteRule ^(.*)$ /index.php/$1 [L]
然后找到application/config/config.php文件：
将$config['index_page'] = "index.php";改为$config['index_page'] = "";
