Add PDF functionality with WinForms

This guide explains how to integrate Nutrient .NET SDK (formerly known as GdPicture.NET SDK) into your application.

About Nutrient .NET SDK

Nutrient .NET SDK is a cross-platform developer solution for building intelligent PDF and document processing applications. This toolkit enables you to compose, display, capture, edit, and print documents. You can build applications using Nutrient .NET SDK with numerous development environments and deploy these applications to different platforms.

Prerequisites

Before proceeding with this guide, ensure your development environment meets the following requirements.

.NET 8.0 or higher (cross-platform)

.NET SDK 8.0 or higher — Install the latest stable version from the Microsoft website(opens in a new tab).
Supported operating systems — Windows, macOS, and Linux.
Development tools — Visual Studio 2022 (17.6+) or Visual Studio Code with C# extension.
Command-line tools — Ensure the .NET CLI is available and configured in your system path.

.NET Framework 4.6.2 or higher (Windows)

.NET Framework 4.6.2+ — Preinstalled on Windows or available from the official Microsoft Download Center.
Supported operating systems — Windows 10 or later.
Development tools — Visual Studio 2019 (or newer) with the .NET framework development workload installed.

For more information on the supported frameworks and operating systems, refer to our system compatibility guide.

Installing Nutrient .NET SDK

The best way to install Nutrient .NET SDK is through NuGet repositories. To view a list of available packages, refer to the download Nutrient .NET guide.

Alternatively, use our ready-made bootstrap project for new setups.

Download example project

Adding Nutrient .NET SDK to your application

This section explains how to integrate Nutrient .NET SDK (formerly GdPicture.NET SDK) into your project.

Adding a reference to the NuGet package

From Visual Studio:

Open Visual Studio and create a new project or load an existing one. To create a new project, refer to the Microsoft documentation(opens in a new tab). We recommend using .NET 8.0 or higher.
In Solution Explorer, right-click your project.
Select Manage NuGet Packages.
Set the Package source to nuget.org.

Select GdPicture, and click Install.

From the command line:

(Optional) Create a new project:
```
dotnet new console -n <ProjectName>
```

Add the GdPicture.API package to the project:

dotnet add <ProjectName>.csproj package GdPicture.API

Importing Nutrient .NET SDK to your application

To use Nutrient .NET SDK, add a reference at the beginning of each code file where you implement its features:

C#
VBNET

using GdPicture14;

Imports GdPicture14;

For more information on the using directive in C#, refer to the Microsoft documentation(opens in a new tab).

Activating the trial license

To activate a trial license, follow the steps below:

In Visual Studio, create a LicenseManager object in the code file where the application loads before using any of the methods of Nutrient .NET SDK.
Pass the license key to the RegisterKEY method of the LicenseManager object.

Set the license using the LicenseManager once before making any calls to the SDK. This activates the license for the entire assembly. Make sure your application initializes and sets the license only once.

LicenseManager licenseManager = new LicenseManager();
licenseManager.RegisterKEY("");

Dim licenseManager As New LicenseManager
licenseManager.RegisterKEY("")

CLicenseManager licenseManager;
licenseManager.CreateDispatch(L"GdPicture14.LicenseManager");
licenseManager.RegisterKEY(L"");

BSTR bstrLicense = ::SysAllocString(L"");
if (bstrLicense != NULL)
{
   _LicenseManagerPtr licenseManager(__uuidof(LicenseManager));
   VARIANT_BOOL result = licenseManager->RegisterKEY(bstrLicense);
   ::SysFreeString(bstrLicense);
}

BSTR bstrLicense = ::SysAllocString(L"");
if (bstrLicense != NULL)
{
   _LicenseManagerPtr licenseManager;
   licenseManager = (_LicenseManagerPtr)CreateComObject(CLSID_LicenseManager);
   licenseManager->RegisterKEY(bstrLicense);
   ::SysFreeString(bstrLicense);
   bstrLicense = NULL;
}

var
   LicenseManager1: Variant;
begin
   LicenseManager1 := CreateOleObject('GdPicture14.LicenseManager');
   LicenseManager1.RegisterKey('');

var licenseManager;
licenseManager = new ActiveXObject("GdPicture14.LicenseManager");
licenseManager.RegisterKey("");

long ll_result
OLEObject licenseManager
licenseManager = CREATE OLEObject
ll_result = licenseManager.ConnectToNewObject("GdPicture14.LicenseManager")
licenseManager.RegisterKey("")

Dim licenseManager As New LicenseManager
Call licenseManager.RegisterKEY("")

Dim licenseManager As New GdPicture_NET_14.LicenseManager
licenseManager.RegisterKey ("")

Leaving the license key as an empty string activates the SDK in trial mode. After purchasing a commercial license, replace the empty string with your license key.

Starting from version 14.2.94, a trial key is no longer required. As shown in the examples above, setting the key to an empty string ("") enables trial mode.