Yii2 上传文件

$files = UploadedFile::getInstancesByName('file');
foreach($files as $key=>$file)
{
$model = new UploadForm();
$model->file= $file;

$dstFile = Yii::$aliases['@runtime'] . '/uploads/' . Yii::$app->shop->id . "_" . Yii::$app->user->id . "_" . rand(0, 99999) . $model->file->name;
if (!file_exists(dirname($dstFile))) {
mkdir(dirname($dstFile), 0755, true);
}
$model->file->saveAs($dstFile);
}

$model = new UploadForm();

$model->file = UploadedFile::getInstanceByName('file');

$dstFile = Yii::$aliases['@runtime'] . '/uploads/' . Yii::$app->shop->id . "_" . Yii::$app->user->id . "_" . rand(0, 99999) . $model->file->name;
if ($model->validate()) {
if (!file_exists(dirname($dstFile))) {
mkdir(dirname($dstFile), 0755, true);
}
$model->file->saveAs($dstFile);
}