关于API快速入门接口的问题 [ 新手入门 ]

跟着教程走完，你应该在控制器里添加下面代码

 public function behaviors()
{
    $behaviors = parent::behaviors(); // TODO: Change the autogenerated stub
    $behaviors['contentNegotiator'] =[
        'class' => yii\filters\ContentNegotiator::className(),
        'formats' => [
            'application/json' => Response::FORMAT_JSON
        ]
    ];
    return $behaviors;
}