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.
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