C#

We have developed a .NET DLL using Visual studio 2015 targeted to .NET framework 4.0 . 
We need to implement the licensing functionality for Design time and runtime .
Could you please suggest the best way to do that.

Note: This is just a .NET DLL NOT a component 

async void OnGenerateMapData()
{
	statusPanel = new StatusPanel();
			
	// add tasks to complete to panel - this causes error
	statusPanel.AddTask(new Task("Processing Map Data", 1081 * 1081, true, new System.Threading.Tasks.Task(() => { ProcessPixelData(); })));
	statusPanel.AddTask(new Task("Generating Shoreline", 1079 * 1079 + 50000, true, new System.Threading.Tasks.Task(() => { ProcessShoreline(); })));
	statusPanel.AddTask(new Task("Updating Map", 1081 * 1081, true, new System.Threading.Tasks.Task(() => { UpdateResult(); })));
	// add panel to UI
	statusPanel.Dock = DockStyle.Fill;
	this.Controls.Add(statusPanel);
	//statusPanel.BringToFront();
			
	Task currentTask = statusPanel.BeginTasks();
	while (currentTask != null)
	{
		await currentTask.Action;
		currentTask = statusPanel.AdvanceCurrentTask(0);
	}

	this.Controls.Remove(statusPanel);
	statusPanel = null;
}

public class Task
{
	bool displayAsPercent;
	int currentItem;
	int totalItems;
	object result;

	public System.Threading.Tasks.Task Action { get; private set; }
	public string Description { get; private set; }
	public bool IsComplete { get { return currentItem >= ItemCount; } }
	public int TotalItems { get { return totalItems; } }
	public object Result { get { return result; } }
	public object Baggage { get; private set; }
	public bool Started { get { return currentItem > 0; } }

	public int ItemCount 
	{
		get
		{
			if (displayAsPercent)
				return 100;
			else
				return totalItems;
		}
	}

	public int CompletedValue
	{
		get
		{
			if (displayAsPercent)
				return (int)((float)((float)currentItem / (float)ItemCount) * 100.0f + 0.5f);
			else 
				return currentItem;
		}
	}

	public Task(string description, int stepCount, bool displayAsPercent, System.Threading.Tasks.Task task)
	{
		currentItem = 0;
		Description = description;
		totalItems = stepCount;
		this.displayAsPercent = displayAsPercent;
		Action = task;
	}

	public void Begin(Task previous) { if (previous != null) Baggage = previous.Result; ++currentItem; }
	public void Advance() { ++currentItem; }
	public void Advance(int increase) { currentItem += increase; }
	public void Complete() { currentItem = totalItems; }
	public void Finalize(object result) { this.result = result; }
}