用Yii，Mysql下载longblob文件（adobe Illustrator或png）

Question

I am trying to download ai/png from mysql DB but all I get is an empty file. On the table I only have id and two longblob (file_ai, file_png). For example, file adobe illustrator view is:

echo CHtml::link('<span class="glyphicon glyphicon glyphicon-download-alt" aria-hidden="true"></span>', 
array('User/downloadFile', 'id' => $file->id, 'ext' => 'application/illustrator'), 
$htmlOptions = array('class' => 'toolMes', 'download', 'data-toggle' => 'tooltip', 'data-placement' => 'bottom', 'title' => 'Download Ai'));

In the controller:

public function actionDownloadFile($id, $ext) {
        $file = Files::model()->findByPk($id);
        if ($ext === 'application/illustrator') {
            header("Content-length:" . strlen($file->file_ai));
            header("Content-type: " . $ext . "");
            header('Content-Disposition: attachment; filename="' . $file->id . '_' . date("Y-m-d") . '.ai"');
        } else {
            header("Content-length:" . strlen($file->file_png));
            header("Content-type: image/png");
            header('Content-Disposition: attachment; filename="' . $file->id . '_' . date("Y-m-d") . '"');
        }
    }

Hope it is enough to have your precious suggestions

Answer 1

Your not echoing out the actual file contents!

If you are storing images in your database you need to do the echo after you throw the headers...

echo $file->file_ai;