我正在使用一个使用CLLocationManager的iPhone应用程序。当用户进行运行时,它会在mapView上显示运行路径。我正在使用以下代码在mapView上绘制运行路径:
double leastDistanceToRecord = 0.0000905;
- (void) locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
if (newLocation.horizontalAccuracy >= 0) {
if (!runoPath)
{
NSLog(@"in !runoPath if");
// This is the first time we're getting a location update, so create
// the RunoPath and add it to the map.
runoPath = [[RunoPath alloc] initWithCenterCoordinate:newLocation.coordinate];
[map addOverlay:runoPath];
self.currentRunData = [[RunData alloc] init];
[currentRunData startPointLocation:newLocation];
// On the first location update, zoom map to user location
MKCoordinateRegion region =
MKCoordinateRegionMakeWithDistance(newLocation.coordinate, 1000, 1000);
[map setRegion:region animated: NO];
}
else
{
// This is a subsequent location update.
// If the runoPath MKOverlay model object determines that the current location has moved
// far enough from the previous location, use the returned updateRect to redraw just
// the changed area.
double latitudeChange = fabs(newLocation.coordinate.latitude - oldLocation.coordinate.latitude);
double longitudeChange = fabs(newLocation.coordinate.latitude - oldLocation.coordinate.longitude);
if (latitudeChange > leastDistanceToRecord || longitudeChange > leastDistanceToRecord) {
MKMapRect updateRect = [runoPath addCoordinate:newLocation.coordinate];
if (!MKMapRectIsNull(updateRect))
{
// There is a non null update rect.
// Compute the currently visible map zoom scale
MKZoomScale currentZoomScale = map.bounds.size.width / map.visibleMapRect.size.width;
// Find out the line width at this zoom scale and outset the updateRect by that amount
CGFloat lineWidth = MKRoadWidthAtZoomScale(currentZoomScale);
updateRect = MKMapRectInset(updateRect, -lineWidth, -lineWidth);
// Ask the overlay view to update just the changed area.
[runoPathView setNeedsDisplayInMapRect:updateRect];
}
// [currentRunData updateLocation:oldLocation toNewLocation: newLocation];
}
[currentRunData updateLocation:oldLocation toNewLocation: newLocation];
// }
}
}
}
问题在于,当我开始跑步时,我得到一些额外的分数,然后由于这些点,我在mapView上得到一条无法反映实际运行的无关线。它甚至发生在我在iPhone上安装应用程序并首次运行时。我不知道为什么它会增加这些额外的积分。任何人都可以帮助我吗?提前谢谢。
答案 0 :(得分:2)
您获得的第一个位置通常是缓存位置且已过时。您可以检查位置的年龄以及是否旧(> 60秒或其他),然后忽略该位置更新。请参阅此答案here。
- 编辑 - 如果您仍然遇到问题,请将此代码放入didUpdateToLocation:并向我们展示NSLog的实际输出(您可以编辑您的问题并添加输出):
NSTimeInterval age = -[newLocation.timestamp timeIntervalSinceNow];
NSLog(@"age: %0.3f sec, lat=%0.2f, lon=%0.2f, hAcc=%1.0f",
age, newLocation.coordinate.latitude, newLocation.coordinate.longitude,
newLocation.horizontalAccuracy);