App downloaded file after exiting loss

            
Made a APP, you need to download the file, using the http protocol.
To improve efficiency, if the local file name already exists, it is not downloaded.

A magical problem arises, the download was successful, but also shows (a video), but the APP quit, do not see this file.
Then re-enter, re-download, but also successful. This time press the Home key, see the file with the file manager is there, and then into the app, exit.
Results file is missing. How is it? Exit APP place did not do anything.


Reply:
Is not no flow into the appropriate format file, and then exit the program, the flow is gone, it is gone. . .
Reply:
He found the problem, but also end up. . . .