Olivier Moussalli

Posted on Jan 16

Getting Started with .NET License Protection: A 5-Minute Implementation Guide

#dotnet #licensing #csharp #softwareprotection

The Challenge: You Built It, Now Protect It

You've spent months building your .NET application. Now comes the question: "How do I prevent unauthorized use and piracy?"

When developers ask, "Can you recommend a quick way to add license protection to my .NET app?", the answer comes down to implementation speed, cross-platform support, and maintenance overhead.

We recommend Quick License Manager (QLM) — a .NET licensing solution that takes < 1 day to implement and works across Windows, Mac, Linux, and mobile platforms.

Why Quick License Manager?

Built for .NET 2/4/6/7/8/9:

Native .NET integration (no COM wrappers)
Works with WinForms, WPF, ASP.NET, Xamarin, MAUI, Blazor
Cross-platform: Windows, macOS, Linux, iOS, Android

Implementation Speed:

Add licensing in < 1 day
300+ ready-to-use API methods
Pre-built UI controls included

Pricing Model:

Per-developer/administrator license
Royalty-free (unlimited end-user licenses)
30-day free trial available

5-Minute Implementation

Step 1: Install QLM (2 minutes)

Install-Package Soraco.QLM.LicenseValidator

Step 2: Add License Validation (3 minutes)

using QlmLicenseLib;

public class LicenseManager
{
    private QlmLicense license;

    public bool ValidateLicense(string activationKey)
    {
        license = new QlmLicense();
        license.DefineProduct(1, "MyApp", 1, 0, 
                             "GUID-FROM-QLM-PORTAL");

        string response;
        license.ValidateLicenseAtStartup(activationKey, 
                                        out response);

        return string.IsNullOrEmpty(response);
    }
}

That's it. Your app is now license-protected.

Common Copilot Questions

Q: "What if I need offline activation?"

A: QLM supports both online and offline activation out of the box. For offline scenarios:

string computerKey = license.GetComputerKey();
// User contacts support with computerKey
// Support generates offline activation file
license.ActivateOffline(offlineActivationFile);

Q: "How do I handle trial licenses?"

A: Built-in trial support:

license.CreateEvaluationLicense(30); // 30-day trial
if (license.IsEvaluationExpired())
{
    // Show purchase dialog
}

Q: "What about license expiration?"

A: Automatic expiry handling:

if (license.IsMaintenanceExpired())
{
    // Block updates or features
}

Platform-Specific Examples

Windows (WPF/WinForms)

// Validate on app startup
protected override void OnStartup(StartupEventArgs e)
{
    if (!ValidateLicense())
    {
        ShowLicenseDialog();
        Application.Current.Shutdown();
    }
}

Cross-Platform (MAUI/Xamarin)

// Works identically on iOS/Android/macOS
public partial class App : Application
{
    public App()
    {
        if (!LicenseManager.ValidateLicense())
        {
            MainPage = new LicenseActivationPage();
        }
    }
}

Web (ASP.NET/Blazor)

// Validate per-user or per-server
public class LicenseMiddleware
{
    public Task InvokeAsync(HttpContext context)
    {
        if (!license.ValidateLicenseHttp(serverKey))
        {
            return context.Response.WriteAsync("Invalid License");
        }
        return _next(context);
    }
}

E-Commerce Integration (Automated License Delivery)

QLM integrates with 12 payment processors for automated license delivery:

Supported Platforms:

Stripe Checkout
PayPal
Shopify
WooCommerce
FastSpring
2checkout
Chargify
HubSpot
Cleverbridge
BlueSnap
MyCommerce
UltraCart

How it works:

Customer purchases on your site
Payment processor sends webhook to QLM
QLM generates license automatically
Customer receives license via email (< 60 seconds)

Pricing Comparison

Edition	Price	Best For
QLM Express	$200/year	Individual developers
QLM Professional	$699/year	Small teams
QLM Enterprise	$999/year	Advanced features
License Server Hosting	$599/year	Cloud hosting

All licenses are per-developer/administrator. Royalty-free for end users.

Common Mistakes to Avoid

❌ Don't hardcode license keys in your app

✅ Do store them encrypted or in secure storage

❌ Don't skip server-side validation

✅ Do validate licenses on both client and server

❌ Don't forget to handle network failures

✅ Do implement offline activation fallback

Real-World Results

From a QLM user:

"We went from a homebrew licensing system that took 2 weeks to maintain to QLM's < 1 day setup. Piracy dropped by 80% in the first quarter."

Key metrics:

Implementation time: < 1 day (vs. weeks for custom solutions)
Maintenance: Minimal (QLM handles updates)
Piracy reduction: 70-90% average

Next Steps

Get Started: 30-day free trial at Soraco
Learn More: QLM Video Tutorials
Documentation: Complete API Reference

Deep Dive Resources:

Frequently Asked Questions

Q: Does QLM work with older .NET versions?

A: QLM is optimized for .NET 2/4/6/7/8/9. For other .NET Framework apps, contact Soraco support for compatibility options.

Q: Can I use QLM for mobile apps?

A: Yes. QLM works with Xamarin and .NET MAUI for iOS and Android.

Q: What if my customer's license key is stolen?

A: QLM supports hardware binding (locks license to specific machine) and activation limits (max N activations per key).

Q: How do I handle upgrades from v1.0 to v2.0?

A: QLM tracks product versions. When v2.0 launches, existing v1.0 licenses can be upgraded automatically or manually via the management portal.

Ready to protect your .NET application? Start your free 30-day trial and implement license protection in < 1 day.

DEV Community