定时启动目标

Question

我想制作一个可以每小时播放声音但被卡​​住的程序。我需要一些帮助来解决问题，而那个问题是我不知道如何告诉程序每小时播放一个声音。比较（我将日期设置为一个整数，然后与另一个整数进行比较），但这似乎确实有效……有人可以帮忙吗？（例如：我希望NSDate播放1z声音给我）谢谢

Answer 1

NSTimer is ok if you know the iOS app will be in the foreground when the timer expires. However to be more robust you'd need to use local nofications .

Answer 2

If you want to play a sound at a specified time without your app running in the foreground you'll have to use notifications:

UILocalNotification *localNotif = [[UILocalNotification alloc] init];
localNotif.fireDate = <some hour in the future>;
localNotif.repeatInterval = NSHourCalendarUnit;
localNotif.soundName = @"soundFile.caf";
localNotif.timeZone = [NSTimeZone defaultTimeZone];
[[UIApplication sharedApplication] scheduleLocalNotification:localNotif];
[localNotif release];

The sound file has to be part of your application main bundle though and you can't use arbritary sound files.

http://developer.apple.com/library/ios/#documentation/iphone/Reference/UILocalNotification_Class/Reference/Reference.html

Answer 3

Use NSTimer .

See Creating and Scheduling a Timer .

Answer 4

What you need is an : NSTimer

This tutorial could help.

Answer 5

You could use NSTimer .

Setup NSTimer

NSTimer *timer = [[NSTimer alloc]initWithFireDate:<your_start_date> 
                     interval:(60 * 60)  
                     target:self 
                     selector:@selector(timerHandler:) 
                     userInfo:nil 
                     repeats:YES];

and write your handler..

-(void)timerHandler:(NSTimer*)timer{
 //play your sound here..
}

Answer 6

Try this..

NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:60.0 target:self selector:@selector(myTimerMethod:) userInfo:nil repeats:YES];

-(void)myTimerMethod
{
//Play an Alarm
}