无法通过removeLocationUpdates()停止Fused Location Provider问题求助

问题根源分析 #

1. 每次调用startLocationUpdates()都会创建新的LocationCallback实例，stopLocationUpdates()只能移除当前持有的回调，之前注册的回调仍在后台运行，导致位置更新停不下来。
2. onResume()中无条件调用startLocationUpdates()，会重复注册多个位置回调，形成多份活跃监听。
3. 触发跳转逻辑时，未先停止位置更新就启动新Activity并结束当前页面，残留的回调会持续触发距离判断，导致ExerciseActivity被重复启动。

修复方案及代码调整 #

1. 类级别初始化回调，添加状态标记

在类中提前初始化LocationCallback，并增加布尔变量标记位置更新状态，避免重复注册：

class MapActivity : AppCompatActivity() {

    private val requestPermissionsRequestCode = 1
    private lateinit var fusedLocationClient: FusedLocationProviderClient
    // 提前初始化回调，确保始终操作同一个实例
    private val locationCallback = object : LocationCallback() {
        override fun onLocationResult(locationResult: LocationResult) {
            for (location in locationResult.locations) {
                // 更新用户位置标记
                mUserMarker.position = GeoPoint(location.latitude, location.longitude)
                mUserMarker.setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_BOTTOM)
                mUserMarker.title = getString(R.string.your_position)
                // 优化：避免重复添加Marker，先判断是否已存在
                val existingMarker = map.overlays.find { it == mUserMarker }
                if (existingMarker == null) {
                    map.overlays.add(mUserMarker)
                }
                map.controller.setCenter(mUserMarker.position)

                if (nextCheckpoints.isNotEmpty()) {
                    // 标记是否已触发跳转，避免多个checkpoint同时满足条件时重复启动
                    var hasTriggeredJump = false
                    for (checkpoint in nextCheckpoints) {
                        if (hasTriggeredJump) break
                        
                        val results = FloatArray(3)
                        Location.distanceBetween(
                            checkpoint.latitude,
                            checkpoint.longitude,
                            location.latitude,
                            location.longitude,
                            results
                        )
                        val distance = results[0]
                        Log.d("Distance: ", distance.toString())
                        if (distance <= 15) {
                            // 先停止位置更新，再执行跳转
                            stopLocationUpdates()
                            val i = Intent(this@MapActivity, ExerciseActivity::class.java)
                            i.putExtra("exerciseId", checkpoint.exercise.exerciseId)
                            startActivity(i)
                            finish()
                            hasTriggeredJump = true
                        }
                    }
                }
            }
        }
    }
    private lateinit var locationRequest: LocationRequest
    private var allCheckpoints: List<CheckpointResult> = ArrayList()
    private val mAdapterNextCheckpoints = NextCheckpointAdapter()
    private var nextCheckpoints: ArrayList<CheckpointResult> = ArrayList()
    // 标记位置更新是否已启动，防止重复注册
    private var isLocationUpdatesStarted = false

2. 修改startLocationUpdates()方法，增加状态判断

private fun startLocationUpdates() {
    if (isLocationUpdatesStarted) return // 已启动则直接返回，避免重复注册
    
    locationRequest = LocationRequest.create().apply {
        interval = 4000
        priority = Priority.PRIORITY_HIGH_ACCURACY
    }
    fusedLocationClient.requestLocationUpdates(
        locationRequest,
        locationCallback,
        Looper.getMainLooper()
    )
    isLocationUpdatesStarted = true
}

3. 修改stopLocationUpdates()方法，更新状态标记

private fun stopLocationUpdates() {
    fusedLocationClient.removeLocationUpdates(locationCallback)
    isLocationUpdatesStarted = false
}

4. 调整onResume()逻辑，避免重复启动

override fun onResume() {
    super.onResume()
    if (!isLocationUpdatesStarted) {
        startLocationUpdates()
    }
}

额外优化点 #

• 移除了onCreate()中重复添加Marker的逻辑，改为判断是否已存在，避免地图上堆积大量重复标记。
• 增加hasTriggeredJump标记，防止多个checkpoint同时满足距离条件时，重复启动新Activity。

内容的提问来源于stack exchange，提问作者jpsf