CheapBarcodes

A .NET MAUI Blazor hybrid application for Android and Windows that provides comprehensive barcode scanning and generation capabilities, with support for hardware barcode scanners (RT150 devices) and image-based scanning.

The app doubles as the demo/test frontend for CheapBarcodes.Scanning, the reusable UI-agnostic RT150 scanning library in this repo — consume that package if you need hardware scanning with your own UI.

Features

Hardware Barcode Scanning

• RT150 Device Support: Native integration with RT150 handheld scanners via serial port communication
• Hardware Button Integration: Supports function keys (F1-F5) for triggering scans
• Dual Scanning Methods:
  • Primary: SerialPort scanning (9600 baud, Com0)
  • Fallback: BroadcastReceiver intent-based scanning
• Audio & Haptic Feedback: System sound playback and vibration confirmation on successful scans
• Lifecycle Management: Automatic start/stop/pause handling with Android activity lifecycle

Image Barcode Scanning

• File Upload: Support for .jpg, .jpeg, .png, .bmp, and .gif image formats
• Async Processing: Non-blocking image analysis with progress indicators
• Multiple Format Detection: Automatic barcode format recognition

Barcode Generation

• Text-to-Barcode: Generate barcodes from any text input
• Customizable Dimensions: Width (50-500px) and height (20-200px) configuration
• Format: Outputs JPEG images as base64 data URIs for inline display
• Live Preview: Instant barcode preview after generation

Scan History & Management

• Persistent History: Tracks up to 100 most recent scans
• Detailed Records: Timestamp, barcode data, format, and source (Hardware/Image)
• Data Grid Display: Sortable, filterable table view with MudBlazor DataGrid
• Copy to Clipboard: One-click copy for any barcode in history
• Clear History: Batch delete functionality

User Interface

• Material Design: Built with MudBlazor 9.7.0 component library
• Responsive Layout: Adaptive cards for different screen sizes
• Real-time Status: Live scanning state indicators
• Toast Notifications: Success/error messages with ISnackbar

Technology Stack

Component	Version	Purpose
.NET	11.0 (preview)	Runtime framework
Target Frameworks	net11.0-android, net11.0-windows	Platform targeting
MAUI	10.0.80	Cross-platform app framework
Blazor WebView	10.0.80	Hybrid web UI rendering
MudBlazor	9.7.0	Material Design component library
CheapHelpers.Services	3.6.0	Barcode services (generation, image scanning)

Android Requirements

• Minimum SDK: API 24 (Android 7.0)
• Target SDK: API 36 (Android 16)
• Architecture: armeabi-v7a (32-bit ARM)

Permissions

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.INTERNET" />

Project Structure

CheapBarcodes/
├── Components/
│   ├── Layout/
│   │   ├── MainLayout.razor           # MudLayout with AppBar and Drawer
│   │   └── NavMenu.razor              # Navigation menu
│   ├── Pages/
│   │   ├── Home.razor                 # Welcome page
│   │   └── Scanner.razor              # Main barcode scanner interface
│   ├── Shared/
│   │   └── ProgressButton.razor       # Reusable async button component
│   ├── Routes.razor                   # Blazor router configuration
│   └── _Imports.razor                 # Global using directives
│
├── Services/
│   ├── ApiUploadOptions.cs            # Phone-home settings (Preferences/SecureStorage)
│   └── ScanApiClient.cs               # Posts scans to the configured endpoint
│
├── Platforms/Android/
│   ├── MainActivity.cs                # Thin lifecycle wiring around Rt150ScannerHost
│   ├── MainApplication.cs             # Application class
│   └── AndroidManifest.xml            # Permissions and configuration
│
├── CheapBarcodes.Scanning/            # Reusable RT150 scanning library (NuGet)
│   ├── IHardwareScannerService.cs     # Scanner interface
│   ├── NullHardwareScannerService.cs  # No-op for non-Android targets
│   └── Android/                       # AndroidHardwareScannerService, Rt150ScannerHost, receivers
│
├── CheapBarcodes.Binding/             # CN.Pda scan.jar binding + native libs (NuGet)
│
├── wwwroot/                           # Blazor static assets
├── Resources/                         # MAUI resources (fonts, images, icons)
├── MauiProgram.cs                     # Service registration & app configuration
└── MainPage.xaml                      # BlazorWebView host page

Hardware Scanning Architecture

Flow Diagram

Hardware Scanner Button (F1-F5)
    ↓
KeyReceiver.OnReceive() → ProcessKeyCode
    ↓
TriggerScan() → ScanThread.Scan() (CN.Pda.Scan)
    ↓
Barcode Data → BarcodeReceiver.OnReceive()
    ↓
Handler message → MainActivity.OnScanMessage()
    ↓
AndroidHardwareScannerService.OnScan()
    ↓
Play sound + vibrate + Fire HardwareBarcodeScanned event
    ↓
Scanner.razor → ProcessScannedBarcode()

Native Integration

Scanner integration lives in the reusable CheapBarcodes.Scanning library, which uses the Java interop bindings (CheapBarcodes.Binding) to communicate with:

• CN.Pda.Scan.ScanThread: Controls scanner hardware via serial port
• CN.Pda.Serialport.SerialPort: Low-level serial communication (9600 baud)

Native libraries (libdevapi.so, libirdaSerialPort.so) provide ARM-native implementations for RT150 devices.

Installation & Setup

Prerequisites

1. Visual Studio 2022 (17.14+) or Visual Studio Code
2. .NET 11 SDK (preview)
3. Android SDK (API 24-36)
4. RT150 barcode scanner device (for hardware scanning)

Build Instructions

Visual Studio

1. Clone the repository
2. Open CheapBarcodes.slnx
3. Restore NuGet packages
4. Set build configuration to Debug/Release
5. Select Android emulator or physical device
6. Build solution (Ctrl+Shift+B)
7. Deploy to device (F5)

Command Line

# Clone repository
git clone <repository-url>
cd CheapBarcodes

# Restore dependencies
dotnet restore

# Build project
dotnet build -c Release -f net11.0-android

# Deploy to connected device
dotnet build -c Release -f net11.0-android -t:Run

Configuration

The app automatically configures:

• MudBlazor theme provider with snackbar positioning
• IBarcodeService singleton registration
• Debug logging (in DEBUG builds)

Usage

Starting Hardware Scanning

1. Launch the app on an RT150 device
2. Navigate to "Scanner" page
3. Hardware scanning starts automatically on app launch
4. Use Start/Stop buttons to manually control scanning state
5. Press hardware function keys (F1-F5) to trigger scans
6. Scanned barcodes appear in "Last Scanned" card with audio/haptic feedback

Scanning from Images

1. Navigate to "Scanner" page
2. Click "Select Image" under "Image Scanner" card
3. Choose an image file (.jpg, .png, .bmp, .gif)
4. Wait for processing
5. Result appears in "Last Scanned" card

Generating Barcodes

1. Navigate to "Scanner" page
2. Enter text in "Text to encode" field under "Barcode Generator"
3. Optionally adjust Width (50-500px) and Height (20-200px)
4. Click "Generate Barcode"
5. Barcode image displays below the button

Viewing Scan History

• All scans automatically appear in "Scan History" table
• Click copy icon to copy barcode to clipboard
• Click "Clear History" to delete all records
• History persists across app restarts (up to 100 scans); use Export CSV to share it

API Reference

IHardwareScannerService

Interface for hardware scanner integration (HardwareScannerService.cs:6-16).

public interface IHardwareScannerService
{
    event EventHandler<string> HardwareBarcodeScanned;
    void OnScan(string barcode);
    void StartScanning();
    void StopScanning();
    bool IsScanning { get; }
}

Events:

• HardwareBarcodeScanned: Fired when a barcode is successfully scanned

Methods:

• StartScanning(): Activates hardware scanner and registers receivers
• StopScanning(): Deactivates scanner and unregisters receivers
• OnScan(string barcode): Processes scanned barcode data (triggers sound/vibration)

Properties:

• IsScanning: Current scanning state

IBarcodeService (CheapHelpers.Services)

Interface for barcode generation and image scanning.

// Generate barcode from text (async)
Task<byte[]> GetBarcodeAsync(string input, int height = 30, int width = 100, BarcodeFormat format = BarcodeFormat.CODE_39, CancellationToken cancellationToken = default)

// Scan barcode from image (async)
Task<(string Text, string Format)?> ReadBarcodeAsync(byte[] imageBytes, CancellationToken cancellationToken = default)

// Event when barcode is detected
event Func<string, Task> BarcodeScanned

Usage Example (Scanner.razor:361-365):

var buffer = new byte[file.Size];
await file.OpenReadStream().ReadAsync(buffer);

var scanResult = await BarcodeService.ReadBarcodeAsync(buffer);
if (scanResult.HasValue && !string.IsNullOrEmpty(scanResult.Value.Text))
{
    ProcessScannedBarcode(scanResult.Value.Text, scanResult.Value.Format, "Image");
}

Scanner Page Component

Main UI component (Components/Pages/Scanner.razor).

Key Methods:

• OnHardwareBarcodeScanned(object sender, string barcode): Hardware scan event handler (Line 285)
• OnImageSelected(InputFileChangeEventArgs e): Image upload handler (Line 344)
• GenerateBarcode(): Barcode generation method (Line 390)
• ProcessScannedBarcode(string barcode, string format, string source): Universal scan processor (Line 303)
• AddToHistory(string barcode, string format, string source): History tracking (Line 315)

Data Model (ScanRecord, Line 441-447):

public class ScanRecord
{
    public string Barcode { get; set; }
    public string Format { get; set; }
    public string Source { get; set; }     // "Hardware" or "Image"
    public DateTime Timestamp { get; set; }
}

Development Notes

Service Registration

Services are registered in MauiProgram.cs:22-54:

• HttpClient (2-minute timeout)
• MudServices (snackbar configuration)
• IBarcodeService singleton

Android Lifecycle Integration

MainActivity handles scanner lifecycle (MainActivity.cs:25-128):

• OnCreate: Initialize handler, wait for MAUI, start scanning
• OnStart/OnResume: Register broadcast receivers
• OnPause: Unregister receivers, pause scanning
• OnDestroy: Stop scanning, clean up resources

Event Handling

The app uses multiple event patterns:

• EventHandler<string>: Hardware scanner events
• Func<string, Task>: Async barcode service events
• Handler.Callback: Android message passing

Known Limitations

1. RT150 Specific: Hardware scanning requires RT150 devices (Android); on Windows the hardware scanner card stays inactive
2. No iOS/macOS: Android and Windows only

Contributing

When contributing, ensure:

• Follow existing code style and patterns
• Use MudBlazor components for UI (avoid HTML tags)
• Add XML documentation comments for public APIs
• Test on physical RT150 devices when modifying scanner code
• Update this README for new features

License

[Specify license here]

Support

For issues or questions:

• File issues in the project repository
• Check MudBlazor documentation: https://mudblazor.com/
• Review MAUI documentation: https://learn.microsoft.com/dotnet/maui/

---

Project Status: Production-ready for hardware scanning | Image scanning feature pending implementation