Yii2 自定义组件

basic\components\HelloWidget.php

<?php
namespace app\components;

use yii\base\Widget;
use yii\helpers\Html;

class HelloWidget extends Widget
{
    public $message;

    public function init()
    {
        parent::init();
        if ($this->message === null) {
            $this->message = '您好';
        }
    }

    public function run()
    {
        return Html::encode($this->message);
    }
}

VIEW

<?php
use app\components\HelloWidget;
?>
<?= HelloWidget::widget(['message' => '组件']) ?>