这是我的应用第二次因为 GPS 背景键而被拒绝。这是我正在使用的代码：
-(void)stopGPS{
[self.locationManagerAll stopUpdatingLocation];
self.locationManagerAll.delegate = nil;
locationManagerAll = nil;
self.cloop = 1;
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setValue:[NSNumber numberWithBool:NO] forKey:@"UpdateLocation"];
[prefs setValue:[NSNumber numberWithInt:0] forKey:@"updationTime"];
[prefs synchronize];
[set.gpsOnOff setOn:NO];
[set.settingsTable reloadData];
[self stopThread];
}
-(void)startGPS{
if ([CLLocationManager locationServicesEnabled]){
if(self.locationManagerAll == nil){
self.locationManagerAll = [[CLLocationManager alloc] init];
self.locationManagerAll.delegate = self;
}
self.locationManagerAll.desiredAccuracy = kCLLocationAccuracyHundredMeters;
self.locationManagerAll.distanceFilter = kCLDistanceFilterNone;
[self.locationManagerAll startUpdatingLocation];
}else {
[set.gpsOnOff setOn:NO];
[set.settingsTable reloadData];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Location Service Disabled"
message:@"To re-enable, please go to Settings and turn on Location Service for this app."
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil];
[alert show];
[alert release];
}
}
以上这些函数用于启动或停止 GPS 定位，以下是 GPS 定位的实现：
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if ([oldLocation.timestamp timeIntervalSinceNow] < - 5) return;
if (newLocation.horizontalAccuracy > 5.0) return;
if (newLocation.coordinate.latitude == oldLocation.coordinate.latitude && newLocation.coordinate.longitude == oldLocation.coordinate.longitude) return;
NSString *currentLatitude = [[NSString alloc]
initWithFormat:@"%f",
newLocation.coordinate.latitude];
NSString *currentLongitude = [[NSString alloc]
initWithFormat:@"%f",
newLocation.coordinate.longitude];
[prefs setValue:currentLatitude forKey:@"UpdateLocationLati"];
[prefs setValue:currentLongitude forKey:@"UpdateLocationLongi"];
[prefs synchronize];
[currentLatitude release];
[currentLongitude release];
if (self.cloop == 1) {
/*UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"" message:@"Current location saved." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
[alert release]; */
self.cloop = 0;
[prefs setValue:[NSNumber numberWithInt:60] forKey:@"updationTime"];
[prefs setValue:[NSNumber numberWithBool:YES] forKey:@"UpdateLocation"];
[prefs synchronize];
[set.gpsOnOff setOn:YES];
[set.settingsTable reloadData];
[self startThread];
}
}
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error{
if ([error code] != kCLErrorLocationUnknown) {
[self stopGPS];
UIAlertView *alert = [[UIAlertView alloc] init];
[alert setTitle:@"Location"];
[alert setMessage:@"Unable to get current location"];
[alert setDelegate:self.set];
[alert addButtonWithTitle:@"Cancel"];
[alert addButtonWithTitle:@"Retry"];
[alert show];
[alert release];
}
}
我还使用了一个计时器线程，它每秒更新一次服务器上的位置。当应用程序进入后台时计时器停止，我正在使用此代码来处理此问题：
- (void)applicationDidEnterBackground:(UIApplication *)application{
/*
Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.*/
if ([[UIDevice currentDevice] respondsToSelector:@selector(isMultitaskingSupported)]) { //Check if our iOS version supports multitasking I.E iOS 4
if ([[UIDevice currentDevice] isMultitaskingSupported]) { //Check if device supports mulitasking
UIApplication *application = [UIApplication sharedApplication]; //Get the shared application instance
__block UIBackgroundTaskIdentifier background_task; //Create a task object
background_task = [application beginBackgroundTaskWithExpirationHandler: ^{
[application endBackgroundTask:background_task];
//Tell the system that we are done with the tasks
background_task = UIBackgroundTaskInvalid; //Set the task to be invalid
//System will be shutting down the app at any point in time now
}];
//Background tasks require you to use asyncrous tasks
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
//Perform your tasks that your application requires
//I do what i need to do here.... synchronously...
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if ([[prefs objectForKey:@"updationTime"] intValue] > 0 && [[prefs objectForKey:@"UpdateLocation"] boolValue]) {
self.backgroundTimer = [NSTimer timerWithTimeInterval:[[prefs objectForKey:@"updationTime"] intValue] target:self selector:@selector(backgroundTriggerTimer) userInfo:nil repeats:YES];
NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
[runLoop addTimer:backgroundTimer forMode:NSRunLoopCommonModes];
[runLoop run];
}
[application endBackgroundTask:background_task];
//End the task so the system knows that you are done with what you need to perform
background_task = UIBackgroundTaskInvalid; //Invalidate the background_task
});
}else if (![[UIDevice currentDevice] isMultitaskingSupported]) {
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if ([[prefs objectForKey:@"UpdateLocation"] boolValue]){
[self stopGPS];
}
}
}else if (![[UIDevice currentDevice] isMultitaskingSupported]) {
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if ([[prefs objectForKey:@"UpdateLocation"] boolValue]){
[self stopGPS];
}
}
}
这是我正在使用的线程代码：
-(void)startThread
{
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if ([[prefs objectForKey:@"UpdateLocation"] boolValue]) {
self.updateLocation = [[NSThread alloc] initWithTarget:self selector:@selector(setUpTimerThread) object:nil];
[self.updateLocation start];
}
}
-(void)stopThread{
[self.updateLocation cancel];
updateLocation = nil;
[self.gpsTimer invalidate];
}
-(void)setUpTimerThread
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if ([[prefs objectForKey:@"updationTime"] intValue] > 0) {
self.gpsTimer = [NSTimer timerWithTimeInterval:[[prefs objectForKey:@"updationTime"] intValue] target:self selector:@selector(triggerTimer) userInfo:nil repeats:YES];
NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
[runLoop addTimer:gpsTimer forMode:NSRunLoopCommonModes];
[runLoop run];
}
[pool release];
}
-(void)triggerTimer
{
NSLog(@"***Timer Called after seconds**");
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSString *location = [[[NSString alloc] initWithFormat:@"%f_%f",[[prefs objectForKey:@"UpdateLocationLati"] doubleValue], [[prefs objectForKey:@"UpdateLocationLongi"] doubleValue]] autorelease];
NSString *urlGen = [[[NSString alloc] initWithFormat:@"%@%d/%@",[prefs objectForKey:@"update_user_location"],[[prefs objectForKey:@"USERID"] intValue], location] autorelease];
NSLog(@"urlGen: %@", urlGen);
NSString *rt = [JSONModel stringWithUrl:urlGen];
if (self.alertLoop == 1) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"" message:@"GPS location has been sent. This alert message will only prompt you once." delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
[alert release];
self.alertLoop = 0;
}
NSLog(@"UPDATE LOCATION : %d", [rt intValue]);
}
我完全糊涂了。我不知道我是否错过了什么。任何机构都可以帮助我。