不使用CI的时候，我们可以使用 error_reporting(E_ALL); error_reporting(0); 这类的代码来控制报错级别。当然也可以在类中使用这些语句，不过CI自己已经有控制报错级别的机制在里面了。

也许你不会经常打开index.php，但是修改就在这个文件里面：

/*

*---------------------------------------------------------------

* APPLICATION ENVIRONMENT

*---------------------------------------------------------------

*

* You can load different configurations depending on your

* current environment. Setting the environment also influences

* things like logging and error reporting.

*

* This can be set to anything, but default usage is:

*

* development

* testing

* production

*

* NOTE: If you change these, also change the error_reporting() code below

*

*/

define('ENVIRONMENT', 'development');

/*

*---------------------------------------------------------------

* ERROR REPORTING

*---------------------------------------------------------------

*

* Different environments will require different levels of error reporting.

* By default development will show errors but testing and live will hide them.

*/

if (defined('ENVIRONMENT'))

{

switch (ENVIRONMENT)

{

case 'development':

error_reporting(E_ALL);

break;

case 'testing':

case 'production':

error_reporting(0);

break;

default:

exit('The application environment is not set correctly.');

}

}

ENVIRONMENT 就是来控制报错级别的，默认的有三个选项，development testing production，由上面的switch语句控制。代码已经很清楚了，可以根据自己的需求进行相应更改。