In our app we are downloading zip file from server so we used "createFileAtPath" method for write this zip file into cache folder
But we face problem when iOS device is locked, It is not create file in background mode.
and many another file function is not working when app goes to background
For create file we are using following function.
[NSFileManager defaultManager] createFileAtPath: contents: attributes:]
Please suggest us the proper way to write file in background mode.