Swift Google Maps横屏模式下定位方向显示异常问题求助

问题描述 #

在基于Swift 5.7.2、Xcode 14.2开发的iOS应用中集成Google Map View后，地图显示及相机更新正常，但横屏模式下蓝色定位点的朝向箭头存在90度偏差：竖屏时箭头指向正确（对应手机顶部朝向），切换到横屏后箭头方向与实际朝向偏差90度。

尝试通过GMSMapView.animate(to:)方法设置bearing参数调整，但仅会旋转地图，无法修正定位点本身的朝向。相关代码如下：

// 视图控制器中定义
var navView: GMSMapView! 
var camera = GMSCameraPosition.camera(withLatitude: latitude, longitude: longitude, zoom: 1)
let viewBounds = self.view.bounds
navView = GMSMapView.map(withFrame: CGRect(x: 102, y: 0, width: viewBounds.maxX - 205, height: viewBounds.maxY), camera: camera)
navView.tag = 10
navView.isMyLocationEnabled = true
navView.isTrafficEnabled = true
self.view.addSubview(navView)

// 位置更新代理方法
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    let location = locations.last!
    speed = abs(location.speed)
    altitude = location.altitude
    let coordinate = location.coordinate
    latitude = coordinate.latitude
    longitude = coordinate.longitude
    setSpeeds(speed, timeStamp: Int(UInt64(location.timestamp.timeIntervalSince1970)))
    if let navView = navView {
        let target = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
        navView.animate(to: GMSCameraPosition(target: target, zoom: 15, bearing: location.course, viewingAngle: 0))
    }
}

解决方案 #

方案一：修正横屏时的定位点朝向 #

问题根源在于Google Maps默认使用设备的UI界面方向计算定位点朝向，横屏时设备物理方向与UI方向存在90度偏移，需根据当前界面方向对航向值进行修正：

1. 实现获取当前界面朝向的工具方法：

func currentInterfaceOrientation() -> UIInterfaceOrientation {
    if #available(iOS 13.0, *) {
        return UIApplication.shared.windows.first?.windowScene?.interfaceOrientation ?? .portrait
    } else {
        return UIApplication.shared.statusBarOrientation
    }
}

2. 在位置更新代理中调整航向值并同步到地图：

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    let location = locations.last!
    speed = abs(location.speed)
    altitude = location.altitude
    let coordinate = location.coordinate
    latitude = coordinate.latitude
    longitude = coordinate.longitude
    setSpeeds(speed, timeStamp: Int(UInt64(location.timestamp.timeIntervalSince1970)))
    
    guard let navView = navView else { return }
    let target = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
    var adjustedCourse = location.course
    
    // 根据界面方向修正航向
    let orientation = currentInterfaceOrientation()
    switch orientation {
    case .landscapeLeft:
        adjustedCourse += 90.0
    case .landscapeRight:
        adjustedCourse -= 90.0
    default:
        break
    }
    // 确保角度在0-360范围内
    adjustedCourse = fmod(adjustedCourse, 360.0)
    adjustedCourse = adjustedCourse < 0 ? adjustedCourse + 360.0 : adjustedCourse
    
    // 更新相机方位
    navView.animate(to: GMSCameraPosition(target: target, zoom: 15, bearing: adjustedCourse, viewingAngle: 0))
    // 关键：同步修正后的航向到定位点
    navView.myLocationHeading = adjustedCourse
}

方案二：禁用朝向箭头，仅显示定位点 #

若不需要显示朝向，可通过两种方式实现：

方式1：使用自定义Marker替代默认定位点

• 关闭Google Maps自带的定位点：

// 地图初始化时设置
navView.isMyLocationEnabled = false

• 创建自定义蓝色定位Marker，并在位置更新时同步坐标：

// 视图控制器中定义全局Marker
var userLocationMarker: GMSMarker?

// 地图初始化后创建Marker
userLocationMarker = GMSMarker()
userLocationMarker?.icon = GMSMarker.markerImage(with: .blue)
userLocationMarker?.map = navView

// 位置更新时更新Marker位置
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    let location = locations.last!
    // ... 原有代码 ...
    userLocationMarker?.position = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
}

方式2：隐藏默认定位点的箭头（谨慎使用）

通过遍历地图子视图隐藏箭头，此方式依赖Google Maps内部视图结构，属于非官方API，可能导致App Store审核不通过：

// 在地图首次加载或位置更新后调用
if let myLocationView = navView.subviews.first(where: { $0.accessibilityIdentifier == "myLocation" }) {
    for subview in myLocationView.subviews {
        if subview is UIImageView && subview.frame.width > myLocationView.frame.width / 2 {
            subview.isHidden = true
        }
    }
}

内容的提问来源于stack exchange，提问作者jl118