Maui Permissions

.NET MAUI Permissions — Gotchas & Best Practices

Critical Anti-Patterns

1. Requesting without checking first

// ❌ Shows prompt even if already granted
var status = await Permissions.RequestAsync<Permissions.Camera>();

// ✅ Check first — avoids unnecessary prompts
var status = await Permissions.CheckStatusAsync<Permissions.Camera>();
if (status != PermissionStatus.Granted)
    status = await Permissions.RequestAsync<Permissions.Camera>();

2. Calling permissions in a constructor

Permission APIs are async and require a UI context. Constructors can't await.

// ❌ Blocks the UI thread or throws
public MyViewModel()
{
    var status = Permissions.RequestAsync<Permissions.Camera>().Result;
}

// ✅ Use OnAppearing, a command, or async initialization
protected override async void OnAppearing()
{
    await CheckAndRequestPermissionAsync<Permissions.Camera>();
}

3. Ignoring Denied and Restricted status

// ❌ Only checks for Granted — misses edge cases
if (status == PermissionStatus.Granted) { /* proceed */ }

// ✅ Handle all relevant statuses
switch (status)
{
    case PermissionStatus.Granted: /* proceed */ break;
    case PermissionStatus.Limited: /* iOS partial access */ break;
    case PermissionStatus.Denied:
    case PermissionStatus.Restricted:
        await ShowSettingsPromptAsync(); break;
}

Platform Pitfalls

⚠️ iOS: One-shot permission dialog

iOS shows the system permission dialog only once per permission, ever. After denial, RequestAsync returns Denied immediately without showing UI. You must guide the user to Settings → App → Permission.

⚠️ Android: ShouldShowRationale timing

ShouldShowRationale returns true only after a prior denial (but not after "Don't ask again"). Use it to show explanatory UI before re-requesting:

if (Permissions.ShouldShowRationale<Permissions.Camera>())
{
    await Shell.Current.DisplayAlert("Permission needed",
        "Camera access is required to scan barcodes.", "OK");
}
status = await Permissions.RequestAsync<Permissions.Camera>();

⚠️ Android API 33+: StorageRead/StorageWrite are dead

On Android 13+, StorageRead and StorageWrite always return Granted (scoped storage makes them meaningless). Use granular media permissions instead:

// ❌ Always returns Granted on API 33+ — gives false confidence
await Permissions.RequestAsync<Permissions.StorageRead>();

// ✅ Use the specific media permission
await Permissions.RequestAsync<Permissions.Photos>();       // photo access
await Permissions.RequestAsync<Permissions.Media>();         // audio/video

⚠️ Windows: Most permissions always return Granted

Windows doesn't have runtime permission dialogs for most features. Declare capabilities in Package.appxmanifest instead.

Always-Check-Before-Request Pattern

The recommended pattern handles iOS one-shot and Android rationale:

public async Task<PermissionStatus> CheckAndRequestPermissionAsync<T>()
    where T : Permissions.BasePermission, new()
{
    var status = await Permissions.CheckStatusAsync<T>();
    if (status == PermissionStatus.Granted)
        return status;

    if (status == PermissionStatus.Denied && DeviceInfo.Platform == DevicePlatform.iOS)
        return status; // iOS won't show dialog again

    if (Permissions.ShouldShowRationale<T>())
    {
        await Shell.Current.DisplayAlert("Permission needed",
            "This feature requires the requested permission.", "OK");
    }

    return await Permissions.RequestAsync<T>();
}

Checklist

• [ ] CheckStatusAsync called before every RequestAsync
• [ ] No permission calls in constructors — use OnAppearing or commands
• [ ] All PermissionStatus values handled (Denied, Restricted, Limited)
• [ ] Android: ShouldShowRationale shown before re-requesting
• [ ] iOS: Settings navigation provided for denied permissions
• [ ] Android API 33+: using Photos/Media instead of StorageRead/StorageWrite
• [ ] Manifest/plist declarations match runtime permission requests

Permissions API Reference

Core API

using Microsoft.Maui.ApplicationModel;

// Check current status
PermissionStatus status = await Permissions.CheckStatusAsync<Permissions.Camera>();

// Request permission
status = await Permissions.RequestAsync<Permissions.Camera>();

// Android: check if rationale should be shown after prior denial
bool showRationale = Permissions.ShouldShowRationale<Permissions.Camera>();

PermissionStatus Enum

Available Permissions

Battery, Bluetooth, CalendarRead, CalendarWrite, Camera, ContactsRead, ContactsWrite, Flashlight, LocationWhenInUse, LocationAlways, Media, Microphone, NearbyWifiDevices, NetworkState, Phone, Photos, PhotosAddOnly, PhotosReadWrite, PostNotifications, Reminders, Sensors, Sms, Speech, StorageRead, StorageWrite, Vibrate

Access via Permissions.<Name>, e.g. Permissions.CheckStatusAsync<Permissions.LocationWhenInUse>().

Custom Permissions

Extend BasePlatformPermission and override platform-specific required permissions:

public class ReadExternalStoragePermission : Permissions.BasePlatformPermission
{
#if ANDROID
    public override (string androidPermission, bool isRuntime)[] RequiredPermissions =>
        new (string, bool)[]
        {
            ("android.permission.READ_EXTERNAL_STORAGE", true)
        };
#endif
}

// Usage
var status = await Permissions.RequestAsync<ReadExternalStoragePermission>();

Platform Permission Declarations

Android

Declare permissions in Platforms/Android/AndroidManifest.xml:

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

iOS

Declare usage descriptions in Platforms/iOS/Info.plist:

<key>NSCameraUsageDescription</key>
<string>This app needs camera access to take photos.</string>
<key>NSLocationWhenInUseUsageDescription</key>
<string>This app needs your location for nearby search.</string>

Windows

Most permissions return Granted or Unknown. Declare capabilities in Platforms/Windows/Package.appxmanifest under <Capabilities>.

Mac Catalyst

Follows iOS patterns. Add usage descriptions to Info.plist and entitlements to Entitlements.plist as needed.

DI-Friendly Permission Service

public interface IPermissionService
{
    Task<PermissionStatus> CheckAndRequestAsync<T>() where T : Permissions.BasePermission, new();
}

public class PermissionService : IPermissionService
{
    public async Task<PermissionStatus> CheckAndRequestAsync<T>() where T : Permissions.BasePermission, new()
    {
        var status = await Permissions.CheckStatusAsync<T>();
        if (status == PermissionStatus.Granted)
            return status;

        if (Permissions.ShouldShowRationale<T>())
        {
            await Shell.Current.DisplayAlert("Permission required",
                "Please grant the requested permission to use this feature.", "OK");
        }

        return await Permissions.RequestAsync<T>();
    }
}

// Registration
builder.Services.AddSingleton<IPermissionService, PermissionService>();