Setup application

• flutter add local_auth
• flutter pub get
• flutter pub run build_runner build --delete-conflicting-outputs

To Integrate

• Go to AndroidManifest.xml (Main) add:

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

• Go to MainActivity.kt and replace everything except for package name with:

    import io.flutter.embedding.android.FlutterFragmentActivity
    import io.flutter.plugins.GeneratedPluginRegistrant
    import io.flutter.embedding.engine.FlutterEngine
    import androidx.annotation.NonNull;
  
    class MainActivity: FlutterFragmentActivity() {
        override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
            GeneratedPluginRegistrant.registerWith(flutterEngine);
        }
    }
  
  

Important files:

• lib/infrastructures/local_auth.dart
• lib/main.dart

  
   Future<void> _authenticateUser() async {
    final String res = await LocalAuthApi.authenticate(
      messageReason: 'Authenticate to access app flirt',
    );
    if (res == 'authenticated') {
      // navigate to home page since it is authenticated
      setState(() => _isAuthenticated = true);
    } else if (res == 'NotEnrolled') {
      // informs the user that they need to enroll biometrics such as finger print or face id
      log(res);
    } else if (res.contains('Device is not supported')) {
      // informs the user that they need to setup password either pin,etc.
      log(res);
    } else {
      //if the authenticatoin is failed then app will automatically exitted
      SystemNavigator.pop();
    }
  }
  
  

error usally encountered:

• android build file gradle-wrapper.properties:

   distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
  
  

Credits to:

• Flutter Tutorial - Fingerprint & Touch ID - Local Auth
• Github Code resources