在yii框架中的主题和布局

'components' => [
    'theme' => 'app\theme\MyTheme',
],

namespace app\theme;

use yii\base\Theme;

class MyTheme extends Theme
{
    public function getColors()
    {
        return [
            'primary' => '#ff0000',
            'secondary' => '#00ff00',
        ];
    }

    public function getFonts()
    {
        return [
            'primary' => 'Arial, sans-serif',
            'secondary' => 'Helvetica, sans-serif',
        ];
    }
}

'components' => [
    'layout' => 'main',
],

namespace app\components;

use yii\base\Layout;

class MainLayout extends Layout
{
    public function renderContent($context, $content)
    {
        return $content;
    }
}

public function actions()
{
    return [
        'index' => [
            'class' => 'app\components\MainLayout',
        ],
    ];
}