title: ionic2:how can I use transfer to upload multiple files at the same time?
body: <p>I want to upload several pictures to server at the same time,the native plugin provide <code>transfer</code>,but this plugin can only upload a file at the same time.I don't want to call <code>transfer.upload</code> in <code>while</code> or <code>for</code>.<br>What method can upload multiple files at the same time? Thank you very much for your reply!!!  <a href="http://ionicframework.com/docs/v2/native/transfer/" rel="nofollow noreferrer">http://ionicframework.com/docs/v2/native/transfer/</a></p>