Maui Media Picker

.NET MAUI Media Picker — Gotchas & Best Practices

Common Mistakes

1. Forgetting to check for cancellation

Single-select returns null, multi-select returns an empty list. Not checking causes NullReferenceException.

// ❌ Crashes when user cancels
var photo = await MediaPicker.Default.PickPhotoAsync();
using var stream = await photo.OpenReadAsync();

// ✅ Always check for null / empty
var photo = await MediaPicker.Default.PickPhotoAsync();
if (photo is null) return;
using var stream = await photo.OpenReadAsync();

2. Calling from a background thread

All MediaPicker methods must run on the UI thread or they throw.

// ❌ Will throw on some platforms
await Task.Run(async () => await MediaPicker.Default.PickPhotoAsync());

// ✅ Call directly from a command or event handler on the UI thread
var photo = await MediaPicker.Default.PickPhotoAsync();

3. Not checking IsCaptureSupported

Devices without cameras (emulators, some tablets) will throw if you call capture methods.

// ❌ Crashes on devices without a camera
var photo = await MediaPicker.Default.CapturePhotoAsync();

// ✅ Guard with capability check
if (MediaPicker.Default.IsCaptureSupported)
{
    var photo = await MediaPicker.Default.CapturePhotoAsync();
}

4. Not disposing streams

OpenReadAsync() returns a stream that must be disposed.

// ❌ Leaks the stream
var stream = await photo.OpenReadAsync();
var bytes = ReadAllBytes(stream);

// ✅ Dispose with using
using var stream = await photo.OpenReadAsync();

Platform Pitfalls

⚠️ SelectionLimit is not enforced on Android/Windows

MediaPickerOptions.SelectionLimit is advisory. Always validate the count yourself:

var options = new MediaPickerOptions { SelectionLimit = 5 };
var results = await MediaPicker.Default.PickPhotosAsync(options);
if (results.Count() > 5)
{
    // Warn user or take only the first 5
    results = results.Take(5);
}

⚠️ Android storage permissions split at API 33

• API ≤ 32: needs READ_EXTERNAL_STORAGE / WRITE_EXTERNAL_STORAGE
• API ≥ 33: needs READ_MEDIA_IMAGES / READ_MEDIA_VIDEO (broad storage permissions are ignored)
• Use android:maxSdkVersion="32" on the old permissions to avoid Play Store warnings

⚠️ iOS requires all four plist keys for full functionality

Missing any one of NSCameraUsageDescription, NSMicrophoneUsageDescription, NSPhotoLibraryUsageDescription, or NSPhotoLibraryAddUsageDescription causes a runtime crash when that feature is accessed.

⚠️ Android requires <queries> for camera intents

Without the IMAGE_CAPTURE query in AndroidManifest.xml, CapturePhotoAsync may fail silently on Android 11+ due to package visibility restrictions.

Decision Framework

Checklist

• [ ] All picker calls run on the UI thread
• [ ] Null/empty checks after every pick/capture call
• [ ] IsCaptureSupported guard before capture methods
• [ ] Streams disposed with using
• [ ] Android manifest has both old and new storage permissions with maxSdkVersion
• [ ] Android manifest has <queries> block for camera intent
• [ ] iOS Info.plist has all four usage description keys
• [ ] SelectionLimit validated in code, not trusted from platform

Media Picker API Reference

Core API

Use MediaPicker.Default to pick or capture photos and videos. All methods must run on the UI thread.

Single-select methods (all .NET versions)

All return Task<FileResult?>. A null result means the user cancelled.

Multi-select methods (.NET 10+)

These return Task<IEnumerable<FileResult>>. An empty list means the user cancelled.

MediaPickerOptions (.NET 10+)

Pass MediaPickerOptions to any pick/capture method to control behavior:

var options = new MediaPickerOptions
{
    Title = "Select photos",        // Picker dialog title
    SelectionLimit = 5,             // Max items (0 = unlimited; multi-select only)
    MaximumWidth = 1024,            // Resize max width in pixels
    MaximumHeight = 1024,           // Resize max height in pixels
    CompressionQuality = 80,       // JPEG quality 0–100
    RotateImage = true,             // Auto-rotate per EXIF
    PreserveMetaData = true         // Keep EXIF/metadata
};

var photos = await MediaPicker.Default.PickPhotosAsync(options);

FileResult Usage

var photo = await MediaPicker.Default.PickPhotoAsync();
if (photo is null)
    return; // user cancelled

// Read the stream
using var stream = await photo.OpenReadAsync();

// Useful properties
string fullPath    = photo.FullPath;
string fileName    = photo.FileName;
string contentType = photo.ContentType;

Save to app storage

async Task<string> SaveToAppDataAsync(FileResult fileResult)
{
    var targetPath = Path.Combine(FileSystem.AppDataDirectory, fileResult.FileName);
    using var sourceStream = await fileResult.OpenReadAsync();
    using var targetStream = File.OpenWrite(targetPath);
    await sourceStream.CopyToAsync(targetStream);
    return targetPath;
}

Check Availability Before Capture

if (MediaPicker.Default.IsCaptureSupported)
{
    var photo = await MediaPicker.Default.CapturePhotoAsync();
    // ...
}

Multi-select Example (.NET 10+)

var options = new MediaPickerOptions { SelectionLimit = 10 };
var results = await MediaPicker.Default.PickPhotosAsync(options);

if (!results.Any())
    return; // user cancelled

foreach (var file in results)
{
    using var stream = await file.OpenReadAsync();
    // process each selected photo
}

Platform Permissions

Android

Add to Platforms/Android/AndroidManifest.xml:

<!-- Camera capture -->
<uses-permission android:name="android.permission.CAMERA" />

<!-- Storage: API ≤ 32 (Android 12 and below) -->
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"
                 android:maxSdkVersion="32" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
                 android:maxSdkVersion="32" />

<!-- Storage: API ≥ 33 (Android 13+) -->
<uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
<uses-permission android:name="android.permission.READ_MEDIA_VIDEO" />
<uses-permission android:name="android.permission.READ_MEDIA_AUDIO" />

Also add inside <application>:

<queries>
    <intent>
        <action android:name="android.media.action.IMAGE_CAPTURE" />
    </intent>
</queries>

iOS / Mac Catalyst

Add to Platforms/iOS/Info.plist (and Platforms/MacCatalyst/Info.plist):

<key>NSCameraUsageDescription</key>
<string>This app needs camera access to take photos</string>
<key>NSMicrophoneUsageDescription</key>
<string>This app needs microphone access to record video</string>
<key>NSPhotoLibraryUsageDescription</key>
<string>This app needs photo library access to pick media</string>
<key>NSPhotoLibraryAddUsageDescription</key>
<string>This app needs permission to save photos</string>

Windows

No additional permissions required.