The name 'PageFactory' does not exist in the current context

Question

I'm creating a test automation framework in c#. At the top of the project I have "using OpenQA.Selenium.Support.PageObjects;", however when I try to reference PageFactory.initElements(driver, PageName) I'm seeing the message "The name 'PageFactory' does not exist in the current context".

I thought the PageFactory class was included as part of the Selenium.Support nu get package. Tutorials online seem to reference the PageFactory in the same way I am with no extra imports, is there anything I'm missing?

NuGet packages:

Using Selenium.WebDriver version 3.9.1

Using Selenium.Support version 3.9.1

Using NUnit 3.9.0

Using NUnit3TestAdapter 3.9.0

Microsoft.NET.Test.Sdk 15.5.0

Code below:

using NUnit.Framework;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using OpenQA.Selenium.Support.PageObjects;
using System;
using System.IO;

namespace Framework.TestCases
{
    class TestCase
    {
        [Test]
        public void Test()
        {
            String pathToDrivers = Directory.GetParent(Directory.GetCurrentDirectory()).Parent.FullName + "\\Drivers";
            IWebDriver driver = new ChromeDriver(pathToDrivers);
            String searchTerm = "Search Term";

            driver.Url = "https://website.com/";
            driver.Manage().Window.Maximize();

            HomePage homePage = new HomePage(driver);
            PageFactory.initElements(driver, homePage);
        }
    }
}

Answer 1

I eventually just created a new project, and ported everything over with one difference, the type of project I created was a Visual C# > Test > Unit Test Project, before the project I had created was Visual C# > .Net Core > Class Library project (I was following a tutorial).

I'm not too sure if this changed anything as such or just meant I had a clear project when I re downloaded and installed the NuGet packages, however I can now access the PageFactory class and associated methods. Thanks to everyone who replied.