PIServer.FindChangedPIPoints Method

public IList<PIPointChangeInfo> FindChangedPIPoints(
	int maxCount,
	Object cookie,
	out PIPointChangesCookie nextCookie,
	IEnumerable<PIPoint> filterPoints = null
)

// Get the PIServers collection for the current user and default PIServer.
PIServer myPIServer = new PIServers().DefaultPIServer;

// Cookie used to get changes since the last call
PIPointChangesCookie cookie = null;

// File used to persist the cookie while the process is not running.
try
{
    // Try to open the file containing the persisted cookie
    using (StreamReader reader = new StreamReader("cookie.dat"))
    {
        string json = reader.ReadToEnd();
        cookie = JsonConvert.DeserializeObject<PIPointChangesCookie>(json);
    }
}
catch (FileNotFoundException) { /* Cookie has never been persisted */ }
catch (SerializationException) { /* Cookie could not be read */ }
catch (SecurityException) { /* No permission to read this file */ }
catch (IOException) { /* Some other I/O Exception */ }

// If the cookie is null, initialize it to start monitoring changes
if (ReferenceEquals(cookie, null))
    myPIServer.FindChangedPIPoints(int.MaxValue, null, out cookie);

// Perform the operation 100 times...
for (int loopIndex = 0; loopIndex < 100; loopIndex++)
{
    string piPointName = $"testPoint_{loopIndex}";

    // Create a new point which should cause a change
    PIPoint testPoint = myPIServer.CreatePIPoint(piPointName);

    // Edit the point's name to cause a change
    testPoint.Name = $"{piPointName}_Renamed";

    // Delete the point which should cause a change
    myPIServer.DeletePIPoint(testPoint.Name);

    // Log changes that have occurred since the last call
    IList<PIPointChangeInfo> changes = myPIServer.FindChangedPIPoints(
        int.MaxValue, cookie, out cookie);

    if (!ReferenceEquals(changes, null))
    {
        foreach (PIPointChangeInfo change in changes)
        {
            Console.WriteLine("ID: {0} Action: {1}", change.ID, change.Action);
        }
    }

    // Sleep for three seconds, don't peg the CPU
    System.Threading.Thread.Sleep(3000);
}

try
{
    // Persist cookie so that the process can pick up changes where it left off
    using (StreamWriter writer = new StreamWriter("cookie.dat"))
    {
        JsonSerializer serializer = new JsonSerializer();
        serializer.Serialize(writer, cookie);
    }
}
catch (SerializationException) { /* Cookie could not be written */ }
catch (SecurityException) { /* No permission to write this file */ }
catch (IOException) { /* Some other I/O Exception */ }