phpyii表单title,Yii2设置关键字,描述,标题

1.在控制器controller里用$this->getView() 
设置；
public function actionIndex() {
    $this->getView()->title = 'title ';
    $this->getView()->metaTags['keywords'] = 'keywords';
    $this->getView()->metaTags['description'] = 'description';
    return $this->render('index');
}
2. 在 view ⾥读取。
<?php  echo Html::encode(($this->title ? $this->title . ' - ' : '') . Yii::$app->name); ?>
metaTags['description']) ? $this->metaTags['description'] : ''; ?>" />
metaTags['keywords']) ? $this->metaTags['keywords'] : ''; ?>" /

3.在view里设置title
<?php  $this->title = "设置title"; ?>