How to create thread to checking time?

Question

I have to setting a time to check for update data from server 2times a day, suppose 9AM and 9PM, but i don't know the way to do that.

Create a thread, run every-time and check time current time with setting,if they are equal,so do task? This way is good? I think that's bad performance.

If you factor in the time difference between the current time and the target, it would not be a huge performance hit. I feel that there should be better ways to do it though. — Alex Gittemeier, Jan 23 '13 at 08:26
there are some unique services which can run in the background on iOS, when your application is in sleep mode: _location services_, _audio services_, _VoIP_. every other threads will be suspended and no thread is running when your application is terminated by any reason. — holex, Jan 23 '13 at 08:26

score 2 · Answer 1 · answered Jan 23 '13 at 08:42

maybe when your app is launching , you can get the current time(also can get the timeInterval of current time called timeInterval0) using [NSDate date] and if your current time < 9:00AM today , you can get the timeInterval of 9:00AM today called timeInterval1. and then you can get how many seconds between now and your target time , then use NSTimer to invocation your method ,the delay is the between seconds.

In your method , you can check the update , and you must also to calc the seconds from then between next 9:00 as above.

score 0 · Accepted Answer · edited May 23 '17 at 11:49

Use thread but instead of checking every sec, if it is equal. You could use NSNotification. When the time is the same, it will send a notification to get the data.

You can read this: iOS timed background processing

Can go through this tutorial as well: http://mobile.tutsplus.com/tutorials/iphone/ios-multitasking-local-notifications/

I have reading up as well. Something new for me as well. Best is NSLocalNotifications. Have a look at this: Reminder App

The documentation for Local Notifications: Local Notifications

How to create thread to checking time?

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