使用标题转换用户位置注释 [英] Turning user location annotation with heading

问题描述

我正在尝试更改我的应用中的用户注释，以便它显示通常的蓝点，但是有一个三角形从它上面显示用户面向哪个方向（我宁愿旋转用户注释而不是整个地图，这是MKUserTrackingModeFollowWithHeading所做的事情）。我有一个基本的版本，但它有一些奇怪的行为。

I'm trying to change the User Annotation in my app so that it shows the usual blue dot, but with a triangle coming off of it to show which direction the user is facing (I'd rather rotate the user annotation than the entire map, which is what MKUserTrackingModeFollowWithHeading does). I've got a rudimentary version working, but it has some weird behavior.

首先，一些代码：

-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation {
     if ([annotation isKindOfClass:[MKUserLocation class]]) {
          _userLocationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"userLocationIdentifier"];
          //use a custom image for the user annotation
          _userLocationView.image = [UIImage imageNamed:@"userLocationCompass.png"];

          return _userLocationView;

     } else {
          return nil;
     }

}

-(void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading {

     //rotate user location annotation based on heading from location manager.
     if (!_locatorButton.hidden) {
          CLLocationDirection direction = newHeading.magneticHeading;

          CGAffineTransform transform = CGAffineTransformMakeRotation(degreesToRadians(direction));
          _userLocationView.transform = transform;
     }

}

-(void)GPSButtonPressed:(id)sender {
    if (self.GPSEnabled) {
        //if GPS is already on, disable it.
        _mapview.showsUserLocation = NO;
        [_mapview removeAnnotation:_mapview.userLocation];
        self.GPSEnabled = NO;

        [_locationManager stopUpdatingHeading];

    } else {
        //enable GPS.
        _mapview.showsUserLocation = YES;
        self.GPSEnabled = YES;

        if ([CLLocationManager headingAvailable]) {
            [_locationManager startUpdatingHeading];
        }


    }
}

用户位置注释图像显示正常，并根据标题旋转，但这是有趣的行为：

The user location annotation image shows up fine, and rotates based on the heading, but here are the funny behaviors:

1-注释不符合我的位置 - - 它只停留在一个地方，但以正确的标题旋转。如果我使用GPS按钮关闭GPS，然后将其重新打开，注释会显示在正确的位置，但在我走路时仍然不会跟随。

1- The annotation does not follow my location-- it only stays in one place, but rotates with the correct heading. If I turn off the GPS with the "GPS Button", then turn it back on, the annotation shows up in the correct place, but still won't follow as I walk.

2-如果我滚动地图，注释会弹回到正北方，然后快速旋转到正确的标题，导致恼人的闪烁效果。

2- If I scroll the map, the annotation pops back to due north, then quickly rotates to the correct heading, causing an annoying flickering effect.

3-如果我关闭GPS并删除用户位置，注释将按预期删除，但如果我滚动地图，注释会弹回屏幕而不是隐藏。

3- If I turn off the GPS and remove the user location, the annotation is removed as intended, but if I then scroll the map, the annotation pops back to the screen rather than staying hidden.

我做错了什么？感谢任何有用的提示！

What am I doing wrong? Thanks for any helpful hints!

推荐答案

即使很可能你已经修复了你的问题，我仍然希望分享解决方案，它帮助我解决了类似的问题。

Even if it is likely that you already fixed your 2. problem I still want to share the solution, which helped me with a similar problem.

我遇到了同样的问题：当用户滚动或平移时，我的自定义用户位置箭头旋转总是弹回北方地图。我在这里找到了解决方法： https://stackoverflow.com/a/12753320/2030629

I came across same problem: my custom user location arrow rotation was always popping back to north when the user scrolled or panned the map. I found the fix here: https://stackoverflow.com/a/12753320/2030629

根据作者的说法，它是一个但在ios6中可以通过添加

according to the author it is a but in ios6 and can be fixed by adding

if(is6orMore) {
        [annView setTransform:CGAffineTransformMakeRotation(.001)]; //iOS6 BUG WORKAROUND !!!!!!!
 }

到mapView：viewForAnnotation。

to mapView:viewForAnnotation.

我还在 - mapView：regionDidChangeAnimated：中再次设置了变换。
希望这会让别人感到高兴，因为它让我：）

I also set the transform in - mapView:regionDidChangeAnimated: again. Hope this will make someone else as happy as it made me :)

这篇关于使用标题转换用户位置注释的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！