Add References and Set a License - WinForms C# .NET 6

This tutorial shows how to create a project, add references, and set the license using the LEADTOOLS SDK in a WinForms C# .NET 6 application.

Summary This tutorial covers how to set a license in a WinForms C# application.
Completion Time 10 minutes
Visual Studio Project Download tutorial project (2 KB)
Platform .NET 6 WinForms C# Application
IDE Visual Studio 2022
Development License Download LEADTOOLS
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Required Knowledge

Before any functionality from the SDK can be leveraged, a valid runtime license will have to be set.

For instructions on how to obtain a runtime license refer to Obtaining a License.

Create the Project

Launch Visual Studio and select Create a new project.

Creating a new Visual Studio project.

Select Windows Forms App and click Next.

Creating a new WinForms App .NET6.

Add the project name, and specify the location where the project to be saved to, then click Next.

Adding the Visual Studio project name and location.

Set the project's framework to .NET 6.0 and click Create.

Setting the Visual studio project target framework.

Add LEADTOOLS References

Add the necessary LEADTOOLS references. The references needed depend upon the purpose of the project. References can be added by one or the other of the following two methods (but not both).

NuGet Reference - Add LEADTOOLS References via NuGet

Right-click the C# project in the Solution Explorer and select Manage NuGet Packages...

Selecting Manage NuGet Packages.

Browse for LEADTOOLS, then select any of the LEADTOOLS NuGet packages and install it. Accept LEAD's End User License Agreement.

Installing LEADTOOLS NuGet packages.

Local Reference - Add Reference to LEADTOOLS Local DLLs

To add the LEADTOOLS references locally, perform the following steps:

In the Solution Explorer, right-click Dependencies, and select Add Project Reference.

Adding local assembly reference.

In the Reference Manager, select Browse and then navigate to the directory where the LEADTOOLS Assemblies are located: <INSTALL_DIR>\LEADTOOLS22\Bin\net

Select and add Leadtools.dll, then click OK.

Adding reference to Leadtools.dll.

Add the Set License Code

Now that the LEADTOOLS references have been added to the project, coding can begin. The License unlocks the LEADTOOLS features needed for the project. It must be set before any toolkit function is called. The exact function called depends on the platform used. For details, refer to Setting a Runtime License.

There are two types of runtime licenses:

Right-click on Form1.cs in the Solution Explorer, and select View Code to bring up the code behind the form. Add the following statements to the using block.

using System.Windows.Forms; 
using System.IO; 
using Leadtools; 

In the Form1 class add a new method called SetLicense() and call it in the Form1() constructor. Add the code below to properly set your LEADTOOLS runtime license.

public partial class Form1 : Form 
   public Form1() 
   static void SetLicense() 
      string license = @"C:\LEADTOOLS22\Support\Common\License\LEADTOOLS.LIC"; 
      string key = File.ReadAllText(@"C:\LEADTOOLS22\Support\Common\License\LEADTOOLS.LIC.KEY"); 
      RasterSupport.SetLicense(license, key); 
      if (RasterSupport.KernelExpired) 
         MessageBox.Show("License file invalid or expired."); 
         MessageBox.Show("License file set successfully"); 

Run the Project

Run the project by pressing F5, or by selecting Debug -> Start Debugging.

If the steps are followed correctly, the application runs and a message box displays License file set successfully.

Message box indicating license has been set successfully.


This tutorial showed how to create a new C# .NET 6 WinForms Project, add references via NuGet or local LEADTOOLS DLLs, and set the license.

This is the basis for all C# .NET 6 WinForms applications using the LEADTOOLS SDK. All functionality in the SDK is unlocked via setting a license. SetLicense must be called before calling any other LEADTOOLS SDK methods.

After the SDK is purchased, the evaluation license can be replaced with a valid release license to disable the Nag Message.

See Also

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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.

Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.