PHP Notice – yiiaseErrorException

使用未定义的常量INTL_ICU_VERSION - 假设 'INTL_ICU_VERSION

Yii 框架/2.0.7

$checks[] = 数组（ 'title' => Yii：：t（'base'， $title）， "状态" => "错误"， 'hint' => '安装 INTL 扩展' ); }

    $icuVersion = (defined('INTL_ICU_VERSION')) ? INTL_ICU_VERSION : 0;
    $icuMinVersion = '4.8.1';
    $title = 'PHP - INTL Extension - ICU Version (' . INTL_ICU_VERSION . ')';
    if (version_compare($icuVersion, $icuMinVersion, '>=')) {
        $checks[] = array(
            'title' => Yii::t('base', $title),
            'state' => 'OK'
        );
    } else {
        $checks[] = array(
            'title' => Yii::t('base', $title),
            'state' => 'WARNING'

          'hint' => 'Install INTL Extension'
        );
    }
    $icuVersion = (defined('INTL_ICU_VERSION')) ? INTL_ICU_VERSION : 0;
    $icuMinVersion = '4.8.1';
    $title = 'PHP - INTL Extension - ICU Version (' . INTL_ICU_VERSION . ')';
    if (version_compare($icuVersion, $icuMinVersion, '>=')) {
        $checks[] = array(
            'title' => Yii::t('base', $title),
            'state' => 'OK'
        );
    } else {