hzfinger_fingerprint_sdk 1.0.2 
hzfinger_fingerprint_sdk: ^1.0.2 copied to clipboard
A Flutter plugin for integrating HZFinger Q818 and compatible fingerprint scanners with Android devices. This SDK provides a high-level API to capture, enroll, verify, and manage fingerprint data dire [...]
import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:typed_data'; // Added for image data
import 'package:flutter/services.dart';
// v-- Import matches your project
import 'package:hzfinger_fingerprint_sdk/hzfinger_fingerprint_sdk.dart';
import 'package:permission_handler/permission_handler.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Plugin Example App',
theme: ThemeData(
primarySwatch: Colors.blue,
useMaterial3: true,
),
home: const MyHomePage(title: 'HZFinger Plugin Example'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
String _statusMessage = 'Not Initialized';
Uint8List? _fingerImage;
Uint8List? _currentIsoTemplate; // To store the latest template
Uint8List? _savedIsoTemplate; // To store a template for comparison
StreamSubscription<FingerprintEvent>? _eventSubscription;
bool _isMonitoring = false; // Track monitoring state
@override
void initState() {
super.initState();
initializeScanner();
}
@override
void dispose() {
_eventSubscription?.cancel();
HzfingerFingerprintSdk.close(); // Close also stops monitoring
super.dispose();
}
void initializeScanner() async {
// Request BOTH storage permissions
var storageStatus = await Permission.storage.request();
// Only request manageExternalStorage on Android
var manageStatus = await Permission.manageExternalStorage.request();
if (storageStatus.isGranted && manageStatus.isGranted) {
try {
bool success = await HzfingerFingerprintSdk.init();
if (success && mounted) {
print("Scanner Initialized!");
setState(() {
_statusMessage = "Scanner Initialized!";
});
// Listen to events
_eventSubscription =
HzfingerFingerprintSdk.fingerprintEvents.listen((event) {
if (!mounted) return;
setState(() {
// Always update status message if available
if(event.message != null && event.message!.isNotEmpty){
_statusMessage = event.message!;
}
// Handle specific event types
if (event.type == "image") {
print("Got image with ${event.data?.length} bytes");
_fingerImage = event.data;
// Optionally update status only if no specific message came with image
if(event.message == null || event.message!.isEmpty) {
_statusMessage = "Image Captured!";
}
} else if (event.type == "iso_template") {
print("Got ISO template with ${event.data?.length} bytes");
_currentIsoTemplate = event.data;
// Optionally update status only if no specific message came with template
if(event.message == null || event.message!.isEmpty) {
_statusMessage = 'ISO Template Created';
}
// Optionally clear the image after getting the template
// _fingerImage = null;
} else if (event.type == "status") {
print("Status: ${event.message}");
// Status message is already handled above
}
});
});
} else {
print("Failed to initialize scanner (false returned).");
if (mounted) {
setState(() {
_statusMessage = "Failed to initialize scanner (false returned).";
});
}
}
} catch (e) {
print("Failed to init device: '$e'.");
if (mounted) {
setState(() {
// Display the specific exception message from init()
_statusMessage = e.toString();
});
}
}
} else {
print("Storage and All Files Access permissions are required.");
if (mounted) {
setState(() {
_statusMessage =
"Storage and All Files Access permissions are required.";
});
}
}
}
// Start/Stop Monitoring
Future<void> _toggleMonitoring() async {
try {
if (_isMonitoring) {
await HzfingerFingerprintSdk.stopMonitoring();
if (mounted) {
setState(() {
_isMonitoring = false;
// Status is usually updated by the plugin event,
// but set a default if needed
_statusMessage = "Monitoring Stopped";
});
}
} else {
// Clear previous results before starting
setState(() {
_fingerImage = null;
_currentIsoTemplate = null;
_statusMessage = "Starting monitoring...";
});
await HzfingerFingerprintSdk.startMonitoring();
if (mounted) {
setState(() {
_isMonitoring = true;
_statusMessage = "Monitoring... Place finger";
});
}
}
} catch(e) {
if (mounted) {
setState(() {
_statusMessage = "Error toggling monitoring: ${e.toString()}";
_isMonitoring = false; // Ensure state reflects failure
});
}
}
}
// Save Template
void _saveTemplate() {
if (_currentIsoTemplate != null) {
setState(() {
_savedIsoTemplate = _currentIsoTemplate;
_statusMessage =
'Template Saved (${_savedIsoTemplate!.lengthInBytes} bytes)';
});
} else {
setState(() {
_statusMessage = 'No current template to save';
});
}
}
// Compare Templates
Future<void> _compareTemplates() async {
if (_currentIsoTemplate != null && _savedIsoTemplate != null) {
try {
setState(() {
_statusMessage = 'Comparing templates...';
});
int score = await HzfingerFingerprintSdk.compareTemplates(
template1: _savedIsoTemplate!,
template2: _currentIsoTemplate!,
);
if (mounted) {
setState(() {
_statusMessage = 'Comparison Score: $score';
});
}
} catch (e) {
if (mounted) {
setState(() {
_statusMessage = 'Comparison failed: ${e.toString()}';
});
}
}
} else {
setState(() {
_statusMessage = 'Need both a saved and current template to compare';
});
}
}
// Manual Capture Trigger (Optional)
Future<void> _manualCapture() async {
try {
setState(() {
_fingerImage = null;
_currentIsoTemplate = null;
_statusMessage = 'Manual Capture: Place finger...';
});
await HzfingerFingerprintSdk.startCapture();
} catch(e) {
if(mounted){
setState((){
_statusMessage = 'Manual capture failed: ${e.toString()}';
});
}
}
}
@override
Widget build(BuildContext context) {
// Helper to display template info
Widget templateInfo(String title, Uint8List? template) {
return Expanded( // Use Expanded to divide space
child: Column(
children: [
Text(title, style: const TextStyle(fontWeight: FontWeight.bold), textAlign: TextAlign.center,),
Text(template != null
? '${template.lengthInBytes} bytes'
: 'N/A', textAlign: TextAlign.center,),
// Optionally display first few bytes:
Text(template != null ? template.take(8).map((b) => b.toRadixString(16).padLeft(2, '0')).join(' ') : '',
style: const TextStyle(fontSize: 10),
textAlign: TextAlign.center,
overflow: TextOverflow.ellipsis,
),
],
),
);
}
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: SingleChildScrollView(
child: Center(
child: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'Status:',
style: Theme.of(context).textTheme.headlineSmall,
),
const SizedBox(height: 8),
Container( // Container for status to prevent layout shifts
height: 40, // Give it a fixed height
child: Text(
_statusMessage,
textAlign: TextAlign.center,
style: Theme.of(context).textTheme.bodyLarge,
),
),
const SizedBox(height: 10),
Container(
width: 200,
height: 250,
decoration: BoxDecoration(
border: Border.all(color: Colors.grey),
borderRadius: BorderRadius.circular(8),
color: Colors.black12,
),
child: _fingerImage != null
? Image.memory(
_fingerImage!,
fit: BoxFit.contain,
gaplessPlayback: true, // Prevent flicker on update
)
: const Center(
child: Text('Fingerprint Image'),
),
),
const SizedBox(height: 15),
// Display Template Info
Padding(
padding: const EdgeInsets.symmetric(horizontal: 10.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
crossAxisAlignment: CrossAxisAlignment.start, // Align tops
children: [
templateInfo('Current Template:', _currentIsoTemplate),
const SizedBox(width: 10), // Add spacing
templateInfo('Saved Template:', _savedIsoTemplate),
],
),
),
const SizedBox(height: 25),
// Buttons in Rows for better layout
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
ElevatedButton(
style: ElevatedButton.styleFrom(
padding: const EdgeInsets.symmetric(
horizontal: 20, vertical: 10),
backgroundColor: _isMonitoring ? Colors.redAccent : null,
),
onPressed: _toggleMonitoring,
child: Text(_isMonitoring ? 'Stop Monitoring' : 'Start Monitoring'),
),
const SizedBox(width: 10),
ElevatedButton(
style: ElevatedButton.styleFrom(
padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 10),
),
onPressed: _manualCapture, // Add manual capture button
child: const Text('Manual Capture'),
),
],
),
const SizedBox(height: 12),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
ElevatedButton(
style: ElevatedButton.styleFrom(padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 10)),
onPressed: _currentIsoTemplate == null ? null : _saveTemplate,
child: const Text('Save Current'),
),
const SizedBox(width: 10),
ElevatedButton(
style: ElevatedButton.styleFrom(padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 10)),
onPressed: (_currentIsoTemplate == null || _savedIsoTemplate == null) ? null : _compareTemplates,
child: const Text('Compare'),
),
],
),
const SizedBox(height: 12),
// Keep Enroll button if needed
ElevatedButton(
style: ElevatedButton.styleFrom(
padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 12),
),
onPressed: () {
setState(() {
_statusMessage = 'Starting enrollment for user "test_user"...';
_fingerImage = null;
_currentIsoTemplate = null;
});
HzfingerFingerprintSdk.enroll("test_user");
},
child: const Text('Enroll User "test_user"'),
),
],
),
),
),
),
);
}
}Metadata
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Metadata
A Flutter plugin for integrating HZFinger Q818 and compatible fingerprint scanners with Android devices. This SDK provides a high-level API to capture, enroll, verify, and manage fingerprint data directly from Flutter apps, using the native HZFinger hardware SDK through platform channels.
Repository (GitHub)
View/report issues
Documentation
License
MIT (license)
Dependencies
flutter, plugin_platform_interface
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