项目从Codeigniter 2.2升级至 Codeigniter 3.0的一些注意事项，codeigniter2.2

项目从Codeigniter 2.2升级至 Codeigniter 3.0的一些注意事项，codeigniter2.2

1. 替换掉system目录下所有的文件和文件夹，以及替换掉index.php

2. controllers和models中的文件首字母都需要改成大写：application.php -> Application.php, m_application.php -> M_application.php

3. 替换掉config/mimes.php

4. 把$auto_load['core']从config/autoload.php里移除

5. session库的使用有了较大改变：项目里主要就是修改了unset_user_data函数 

<span>//</span><span> Old</span>
<span>$this</span>->session->unset_userdata(<span>array</span>('item' => '', 'item2' => ''<span>));

</span><span>//</span><span> New</span>
<span>$this</span>->session->unset_userdata(<span>array</span>('item', 'item2'));

6. 更新config/database.php文件

<span>$active_group</span> = 'default'<span>;
</span><span>//</span><span> $active_record = TRUE;</span>
<span>$query_builder</span> = <span>TRUE</span><span>;

</span><span>//</span><span>$db['default']['dbdriver'] = 'mysql';</span>
<span>$db</span>['default']['dbdriver'] = 'mysqli';

7. 把CI3.0 views文件夹下的errors文件夹复制到项目的views文件夹下

8. 更新config/routes.php文件，CI3.0中(:any)不包括'/'

(.+)    <span>//</span><span> matches ANYTHING</span>
(:any)  <span>//</span><span> matches any character, except for '/'</span>

更多信息请查看：http://codeigniter.org.cn/user_guide/installation/upgrade_300.html