can you improve it to support continue download base on downloaded progress?

[tigerface]

hello,there is a issue can be improved.
if I have a very big file to be downloaded(1GB),when downloading 50%, the network is off,I click 'start' button,the download task restart to download from 0, it's not very friendly,can u support continue download base on downloaded progress plz?

[xckevin]

@tigerface
interesting problem. Actually it would resume download after task was canceled or failed. It will persist download task info into database while downloading. And if you restart the task, it will download from latest point.
Of course I test this function successfully. Please check you code again. Good luck.