Maui Geolocation

.NET MAUI Geolocation

Critical: Always Pass a CancellationToken

GetLocationAsync can hang indefinitely if GPS is off, the device is indoors, or permissions are in a pending state. Always set a timeout.

// ❌ Hangs forever if no GPS fix is available
var location = await Geolocation.Default.GetLocationAsync(
    new GeolocationRequest(GeolocationAccuracy.High));

// ✅ Times out after 30 seconds
using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(30));
var location = await Geolocation.Default.GetLocationAsync(
    new GeolocationRequest(GeolocationAccuracy.High), cts.Token);

---

Accuracy vs. Battery Trade-off

Use the lowest accuracy that satisfies your feature. Higher accuracy drains battery significantly faster — especially on Android.

---

Platform Gotchas

iOS 14 reduced accuracy

Users can grant "approximate" location (accuracy > 1 km). Your app receives a location, but it may be useless for precision features.

• Check location.Accuracy — values > 100 m likely indicate reduced precision.
• Use GeolocationRequest.RequestFullAccuracy with a key matching

NSLocationTemporaryUsageDescriptionDictionary in Info.plist to prompt for full accuracy.

Android: mock locations in security-sensitive flows

// ⚠️ Always check in security-sensitive flows (e.g., geofence, check-in)
if (location.IsFromMockProvider)
{
    // Reject — user is spoofing location
}

Android: Altitude 0.0 is not sea level

Some Android devices return 0.0 for Altitude when the GPS has no barometric sensor. Treat 0.0 as "unknown", not sea level.

Android 10+: background location requires separate permission

ACCESS_BACKGROUND_LOCATION must be requested separately from foreground permissions and triggers a distinct system dialog. Requesting it together with foreground permissions causes both to be denied on some devices.

GetLastKnownLocationAsync returns null

This is expected on first boot or after a location-data reset. Always fall back to GetLocationAsync:

// ✅ Cache-first with fresh fallback
var location = await geolocation.GetLastKnownLocationAsync();
if (location is null || location.Timestamp < DateTimeOffset.UtcNow.AddMinutes(-5))
{
    location = await geolocation.GetLocationAsync(
        new GeolocationRequest(GeolocationAccuracy.Medium, TimeSpan.FromSeconds(10)), ct);
}

Permissions must be requested before any geolocation call

Call Permissions.RequestAsync<Permissions.LocationWhenInUse>() first, or catch PermissionException. Calling GetLocationAsync without permission throws on some platforms and returns null on others — inconsistent behaviour across platforms.

---

Continuous Listening: Don't Forget to Unsubscribe

Failing to remove the LocationChanged handler when stopping causes continued GPS usage and battery drain.

// ❌ Forgetting to unsubscribe — GPS stays active
public void StopTracking()
{
    Geolocation.Default.StopListeningForeground();
    // LocationChanged handler still fires!
}

// ✅ Always remove the event handler
public void StopTracking()
{
    Geolocation.Default.StopListeningForeground();
    Geolocation.Default.LocationChanged -= OnLocationChanged;
}

---

Checklist

• [ ] CancellationToken passed to every GetLocationAsync call
• [ ] Accuracy level matched to feature need (not blindly set to Best)
• [ ] GetLastKnownLocationAsync null-check with GetLocationAsync fallback
• [ ] Runtime permissions requested before first geolocation call
• [ ] LocationChanged handler removed when stopping continuous listening
• [ ] Android: ACCESS_BACKGROUND_LOCATION requested separately (if needed)
• [ ] iOS: NSLocationTemporaryUsageDescriptionDictionary added for full-accuracy prompt
• [ ] Android: IsFromMockProvider checked in security-sensitive flows

Geolocation API Reference

Platform Permissions

Android

Add to Platforms/Android/AndroidManifest.xml inside <manifest>:

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<!-- Android 10+ background location (only if needed) -->
<uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />

iOS

Add to Platforms/iOS/Info.plist:

<key>NSLocationWhenInUseUsageDescription</key>
<string>This app needs your location to provide nearby results.</string>

For full-accuracy prompts on iOS 14+, also add:

<key>NSLocationTemporaryUsageDescriptionDictionary</key>
<dict>
  <key>FullAccuracyUsageKey</key>
  <string>This app needs precise location for turn-by-turn directions.</string>
</dict>

macOS (Mac Catalyst)

Add to Platforms/MacCatalyst/Entitlements.plist:

<key>com.apple.security.personal-information.location</key>
<true/>

Windows

No manifest changes required. Location capability is enabled by default.

Core API — Geolocation.Default

One-Shot Location

try
{
    var request = new GeolocationRequest(GeolocationAccuracy.Medium, TimeSpan.FromSeconds(10));
    var cts = new CancellationTokenSource(TimeSpan.FromSeconds(15));
    var location = await Geolocation.Default.GetLocationAsync(request, cts.Token);

    if (location is null)
    {
        // Location unavailable — GPS off, permissions denied, or timeout
        return;
    }

    Console.WriteLine($"{location.Latitude}, {location.Longitude} ±{location.Accuracy}m");
}
catch (FeatureNotSupportedException)
{
    // Device lacks GPS hardware
}
catch (PermissionException)
{
    // Location permission not granted
}

Continuous Listening

public partial class TrackingViewModel : ObservableObject
{
    [ObservableProperty] Location? currentLocation;

    public async Task StartTracking()
    {
        Geolocation.Default.LocationChanged += OnLocationChanged;
        var request = new GeolocationListeningRequest(GeolocationAccuracy.High, TimeSpan.FromSeconds(5));
        var success = await Geolocation.Default.StartListeningForegroundAsync(request);
        if (!success)
            Geolocation.Default.LocationChanged -= OnLocationChanged;
    }

    public void StopTracking()
    {
        Geolocation.Default.StopListeningForeground();
        Geolocation.Default.LocationChanged -= OnLocationChanged;
    }

    void OnLocationChanged(object? sender, GeolocationLocationChangedEventArgs e)
    {
        CurrentLocation = e.Location;
    }
}

GeolocationAccuracy Levels

DI-Friendly Service Wrapper

Register IGeolocation in MauiProgram.cs:

builder.Services.AddSingleton<IGeolocation>(Geolocation.Default);
builder.Services.AddSingleton<LocationService>();

Consume via constructor injection:

public class LocationService(IGeolocation geolocation)
{
    public async Task<Location?> GetCurrentAsync(CancellationToken ct = default)
    {
        var cached = await geolocation.GetLastKnownLocationAsync();
        if (cached is not null && cached.Timestamp > DateTimeOffset.UtcNow.AddMinutes(-5))
            return cached;

        return await geolocation.GetLocationAsync(
            new GeolocationRequest(GeolocationAccuracy.Medium, TimeSpan.FromSeconds(10)), ct);
    }
}