iphone-背靠背為事件進行投票很長一段時間以來，我一直在研究一種在我的iPhone應用程序中每隔X分鐘輪詢一次數據計數器的方法。在閱讀了大量的后臺執(zhí)行文檔和一些試用應用程序之后，我認為在不濫用后臺API的情況下，這是不可能的。上周，我發(fā)現這個應用程序就是這么做的。http：/itunes.apple.com/us/app/DataMan-實時-數據-使用/id3932873？mt=8它在后臺運行，并跟蹤您所使用的蜂窩/WiFi數據的計數。我懷疑開發(fā)人員正在注冊他的應用程序以跟蹤位置變化，但是在應用程序運行時，位置服務圖標是不可見的，我認為這是必需的。有沒有人知道如何做到這一點？
3 回答
九州編程
TA貢獻1785條經驗 獲得超4個贊
// if the iOS device allows background execution,// this Handler will be called- (void)backgroundHandler {
NSLog(@"### -->VOIP backgrounding callback");
// try to do sth. According to Apple we have ONLY 30 seconds to perform this Task!
// Else the Application will be terminated!
UIApplication* app = [UIApplication sharedApplication];
NSArray* oldNotifications = [app scheduledLocalNotifications];
// Clear out the old notification before scheduling a new one.
if ([oldNotifications count] > 0) [app cancelAllLocalNotifications];
// Create a new notification
UILocalNotification* alarm = [[[UILocalNotification alloc] init] autorelease];
if (alarm)
{
alarm.fireDate = [NSDate date];
alarm.timeZone = [NSTimeZone defaultTimeZone];
alarm.repeatInterval = 0;
alarm.soundName = @"alarmsound.caf";
alarm.alertBody = @"Don't Panic! This is just a Push-Notification Test.";
[app scheduleLocalNotification:alarm];
}}- (void)applicationDidEnterBackground:(UIApplication *)application {
// This is where you can do your X Minutes, if >= 10Minutes is okay.
BOOL backgroundAccepted = [[UIApplication sharedApplication] setKeepAliveTimeout:600 handler:^{ [self backgroundHandler]; }];
if (backgroundAccepted)
{
NSLog(@"VOIP backgrounding accepted");
}}- (void)applicationDidEnterBackground:(UIApplication *)application {
UIApplication* app = [UIApplication sharedApplication];
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}];
// Start the long-running task and return immediately.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// you can do sth. here, or simply do nothing!
// All your background treads and timers are still being executed
while (background)
[self doSomething];
// This is where you can do your "X minutes" in seconds (here 10)
sleep(10);
}
// And never call the expirationHandler, so your App runs
// until the system terminates our process
//[app endBackgroundTask:bgTask];
//bgTask = UIBackgroundTaskInvalid;
}); }最新情況：
UIBackgroundTaskIdentifier bgTask;
// if the iOS device allows background execution,// this Handler will be called- (void)backgroundHandler {
NSLog(@"### -->VOIP backgrounding callback");
UIApplication* app = [UIApplication sharedApplication];
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}];
// Start the long-running task
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
while (1) {
NSLog(@"BGTime left: %f", [UIApplication sharedApplication].backgroundTimeRemaining);
[self doSomething];
sleep(1);
} }); - (void)applicationDidEnterBackground:(UIApplication *)application {
BOOL backgroundAccepted = [[UIApplication sharedApplication] setKeepAliveTimeout:600 handler:^{ [self backgroundHandler]; }];
if (backgroundAccepted)
{
NSLog(@"VOIP backgrounding accepted");
}
UIApplication* app = [UIApplication sharedApplication];
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}];
// Start the long-running task
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
while (1) {
NSLog(@"BGTime left: %f", [UIApplication sharedApplication].backgroundTimeRemaining);
[self doSomething];
sleep(1);
}
}); }更新2：
- (void)applicationDidEnterBackground:(UIApplication *)application {
UIApplication* app = [UIApplication sharedApplication];
// it's better to move "dispatch_block_t expirationHandler"
// into your headerfile and initialize the code somewhere else
// i.e.
// - (void)applicationDidFinishLaunching:(UIApplication *)application {//// expirationHandler = ^{ ... } }
// because your app may crash if you initialize expirationHandler twice.
dispatch_block_t expirationHandler;
expirationHandler = ^{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
bgTask = [app beginBackgroundTaskWithExpirationHandler:expirationHandler];
};
bgTask = [app beginBackgroundTaskWithExpirationHandler:expirationHandler];
// Start the long-running task and return immediately.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// inform others to stop tasks, if you like
[[NSNotificationCenter defaultCenter] postNotificationName:@"MyApplicationEntersBackground" object:self];
// do your background work here
}); }
繁花如伊
TA貢獻2012條經驗 獲得超12個贊
什么起作用，什么不起作用
網絡電話攻擊-工作，但是 將要
如果你不是VOIP應用程序，就會被拒絕 遞歸 beginBackgroundTask...-不起作用。10分鐘后它就會退出。即使您嘗試了注釋中的修補程序(至少是截至2012年11月30日的注釋)。 無聲的音頻作品，但是人們因為這個而被拒絕。 本地/推送通知-在您的應用程序被喚醒之前需要用戶交互 使用背景位置-作品
..詳情如下：
下面是它的工作原理：
應用程序不在后臺運行：否 所需背景模式：地點
#import <CoreLocation/CoreLocation.h>CLLocationManager* locationManager = [[CLLocationManager alloc] init]; [locationManager startUpdatingLocation];
startMonitoringSignificantLocationChanges
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