yii2: how to response image and let browser show it?

Question

the same work can be done by follow code：

header(\'Content-Type:image/jpeg\');
readfile(\'a.jpg\');

but now I really confused by Yii2\'s

Answer 1

in yii2 you can return a response object from class yii\web\Response in action. so you can return a own response.

for example display image in yii2 :

public function actionIndex() {
    \Yii::$app->response->format = yii\web\Response::FORMAT_RAW;
    \Yii::$app->response->headers->add('content-type','image/png');
    \Yii::$app->response->data = file_get_contents('file.png');
    return \Yii::$app->response;
}

FORMAT_RAW: the data will be treated as the response content without any conversion. No extra HTTP header will be added.