This tutorial shows how to get started with the LEADTOOLS SDK in a C# .NET Core application.
|Summary||This tutorial covers how to set a license in a C# .NET Core application.|
|Completion Time||30 minutes|
|Visual Studio Project||Download tutorial project (1 KB)|
|Platform||C# .NET Core Application|
|IDE||Visual Studio 2017, 2019|
|Runtime License||Download LEADTOOLS|
|Try it in another language|
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.
Launch Visual Studio and select Create a new project.
Select Console App (.NET Core) and click Next.
Add the project name and specify the location where the project to be saved to and click Create.
To add the LEADTOOLS references in this tutorial, add a LEADTOOLS NuGet package since this will be using .NET Core.
Right-click on the C# project in the Solution Explorer and select Manage NuGet Packages...
Browse for LEADTOOLS, then select any of the LEADTOOLS NuGet packages and install it. You will need to accept LEAD's End User License Agreement.
Now that the LEADTOOLS references have been added to the project, add the relevant code to set your license.
Program.cs in the Solution Explorer, then add
using Leadtools; to the using block at the top.
Program class add a new method called
SetLicense() and call it in the
Main method. Add the below code to properly set your license.
static void Main(string args)
Console.WriteLine("Error setting license");
Console.WriteLine("License file set successfully");
static bool SetLicense()
// TODO: Replace this with your License File contents
string licString = "[License]\n" + "License = <doc><ver>2.0</ver>`PASTE YOUR LICENSE CONTENTS HERE`</doc>";
string developerKey = "PASTE YOUR DEVELOPER KEY HERE";
byte licBytes = System.Text.Encoding.UTF8.GetBytes(licString);
catch (Exception ex)
The project can then be built and run through Visual Studio or the command line provided the deployment environment has .NET Core supported and installed. To install .NET Core, refer to the installation guide on Microsoft's documentation site.
Run the project by pressing F5, or by selecting Debug -> Start Debugging.
If the steps were followed correctly, a message will appear in the console showing
License file set successfully.
Open the terminal and browse to the project directory. Then execute
dotnet build to build the project and
dotnet run to execute it. Other commands include
dotnet rebuild, and
This tutorial covered how to create a new C# .NET Core Project, how to add references via NuGet, and how to execute the project on Windows, Mac and Linux.
This is the basis for all C# .NET Core applications leveraging the LEADTOOLS SDK. All functionality in the SDK is unlocked via setting a license. The
SetLicense method must be called before calling any other LEADTOOLS SDK functions.
Once the SDK is purchased, the evaluation license can be replaced with a valid runtime license to disable the Nag Message.