您好我正在开发带有蜂窝电话的iPad Mini第一代,需要使用其内部GPS来获取纬度/经度坐标。我将在船上并按下一个按钮,将坐标保存到iPad上的文本文件中(文档目录)。然后我将在10英里之外航行并再次点击按钮,将新坐标附加到文本文件中。我将这样做8次,并且应该有8对不同的坐标。但是,应用程序非常不一致,要么保持相同的坐标,要么根本不获取任何坐标。提醒我,我不使用wifi /蜂窝电话,只使用内部GPS(船上的GPS能够获取信号,因此不是硬件问题)。我的代码如下。提前谢谢!
//in viewDidLoad
self.locman = [[CLLocationManager alloc] init];
self.locman.delegate = self;
self.locman.desiredAccuracy = kCLLocationAccuracyBest;
self.locman.distanceFilter = kCLDistanceFilterNone;
self.locman.desiredAccuracy = kCLLocationAccuracyHundredMeters;
//委托方法
#define REQ_ACC 10
#define REQ_TIME 10
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {
CLLocation* loc = locations.lastObject;
CLLocationAccuracy acc = loc.horizontalAccuracy;
NSDate* time = loc.timestamp;
CLLocationCoordinate2D coord = loc.coordinate;
if (!self.startTime) {
self.startTime = [NSDate date];
return; // ignore first attempt
}
NSLog(@"%f", acc);
NSTimeInterval elapsed = [time timeIntervalSinceDate:self.startTime];
if (elapsed > REQ_TIME) {
NSLog(@"%@", @"This is taking too long");
[self stopTrying];
return;
}
if (acc < 0 || acc > REQ_ACC) {
return; // wait for the next one
}
// got it
NSLog(@"You are at: %f %f", coord.latitude, coord.longitude);
self.lat = [NSString stringWithFormat:@"%.8f",coord.latitude];
self.longString = [NSString stringWithFormat:@"%.8f",coord.longitude];
[self stopTrying];
}
-(void) stopTrying {
[self.locman stopUpdatingLocation];
self.startTime = nil;
self.trying = NO;
}
//这是在IBAction中(当用户想要记录坐标时按下按钮)
[self.locman startUpdatingLocation];
答案 0 :(得分:1)
尝试使用pausesLocationUpdatesAutomatically = NO
CLLocationManager
看起来永远不会调用stopTrying
(我猜,因为新初始化time
和elapsed
)所以GPS会自动暂停。
此外,如果您想要此方法的“超时”计时器,则应该在NSTimer
中启动IBAction
并在其中调用stopTrying
和invalidate
计时器太