ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Data.Realtime Namespace / RealtimeCursor Class / MoveNext Method
Example Version

MoveNext Method (RealtimeCursor)
Advances to the next RealtimeRow in this RealtimeCursor. This method can be called on any thread.
Syntax
public bool MoveNext()

Return Value

true if the cursor has successfully advanced to the next row; false if the cursor has passed the end of the collection.
Exceptions
ExceptionDescription
A geodatabase-related exception has occurred.
Remarks
The RealtimeCursor can only advance sequentially forward. To move the cursor back to the beginning, you will have to reexecute the search to obtain a new row cursor.
Example
Search And Subscribe for Streaming Data
await QueuedTask.Run(async () =>
{
  //query filter can be null to search and retrieve all rows
  //true means recycling cursor
  using (var rc = streamLayer.SearchAndSubscribe(qfilter, true))
  {
    //waiting for new features to be streamed
    //default is no cancellation
    while (await rc.WaitForRowsAsync())
    {
      while (rc.MoveNext())
      {
        using (var row = rc.Current)
        {
          //determine the origin of the row event
          switch (row.GetRowSource())
          {
            case RealtimeRowSource.PreExisting:
              //pre-existing row at the time of subscribe
              continue;
            case RealtimeRowSource.EventInsert:
              //row was inserted after subscribe
              continue;
            case RealtimeRowSource.EventDelete:
              //row was deleted after subscribe
              continue;
          }
        }
      }
    }
  }//row cursor is disposed. row cursor is unsubscribed

  //....or....
  //Use the feature class instead of the layer
  using (var rfc = streamLayer.GetFeatureClass())
  {
    //non-recycling cursor - 2nd param "false"
    using (var rc = rfc.SearchAndSubscribe(qfilter, false))
    {
      //waiting for new features to be streamed
      //default is no cancellation
      while (await rc.WaitForRowsAsync())
      {
        //etc
      }
    }
  }
});
Search And Subscribe With Cancellation
await QueuedTask.Run(async () =>
{
  //Recycling cursor - 2nd param "true"
  //or streamLayer.Subscribe(qfilter, true) to just subscribe
  using (var rc = streamLayer.SearchAndSubscribe(qfilter, true))
  {
    //auto-cancel after 20 seconds
    var cancel = new CancellationTokenSource(new TimeSpan(0, 0, 20));
    //catch TaskCanceledException
    try
    {
      while (await rc.WaitForRowsAsync(cancel.Token))
      {
        //check for row events
        while (rc.MoveNext())
        {
          using (var row = rc.Current)
          {
            //etc
          }
        }
      }
    }
    catch (TaskCanceledException )
    {
      //Handle cancellation as needed
    }
    cancel.Dispose();
  }
});
Explicitly Cancel WaitForRowsAsync
//somewhere in our code we create a CancellationTokenSource
var cancel = new CancellationTokenSource();
//...

//call cancel on the CancellationTokenSource anywhere in
//the add-in, assuming the CancellationTokenSource is in scope
if (SomeConditionForCancel)
  cancel.Cancel();//<-- will cancel the token

//Within QueuedTask we are subscribed! streamLayer.Subscribe() or SearchAndSubscribe()
try
{
  //TaskCanceledException will be thrown when the token is cancelled
  while (await rc.WaitForRowsAsync(cancel.Token))
  {
    //check for row events
    while (rc.MoveNext())
    {
      using (var row = rc.Current)
      {
        //etc
      }
    }
  }
}
catch (TaskCanceledException )
{
  //Handle cancellation as needed
}
cancel.Dispose();
Subscribe to Streaming Data
//Note: with feature class we can also use a System Task to subscribe and
//process rows
await QueuedTask.Run(async () =>
{
  // or var rfc = realtimeDatastore.OpenTable(name) as RealtimeFeatureClass
  using (var rfc = streamLayer.GetFeatureClass())
  {
    //non-recycling cursor - 2nd param "false"
    //subscribe, pre-existing rows are not searched
    using (var rc = rfc.Subscribe(qfilter, false))
    {
      SpatialQueryFilter spatialFilter = new SpatialQueryFilter();
      //waiting for new features to be streamed
      //default is no cancellation
      while (await rc.WaitForRowsAsync())
      {
        while (rc.MoveNext())
        {
          using (var row = rc.Current)
          {
            switch (row.GetRowSource())
            {
              case RealtimeRowSource.EventInsert:
                //getting geometry from new events as they arrive
                Polygon poly = ((RealtimeFeature)row).GetShape() as Polygon;

                //using the geometry to select features from another feature layer
                spatialFilter.FilterGeometry = poly;//project poly if needed...
                countyFeatureLayer.Select(spatialFilter);
                continue;
              default:
                continue;
            }
          }                  
        }
      }
    }//row cursor is disposed. row cursor is unsubscribed
  }
});
Search Existing Data and Subscribe for Streaming Data
//Note we can use System Task with the Realtime feature class
//for subscribe
await System.Threading.Tasks.Task.Run(async () =>
// or use ... QueuedTask.Run()
{
  using (var rfc = streamLayer.GetFeatureClass())
  {
    //non-recycling cursor - 2nd param "false"
    using (var rc = rfc.SearchAndSubscribe(qfilter, false))
    {
      //waiting for new features to be streamed
      //default is no cancellation
      while (await rc.WaitForRowsAsync())
      {
        //pre-existing rows will be retrieved that were searched
        while (rc.MoveNext())
        {
          using (var row = rc.Current)
          {
            var row_source = row.GetRowSource();
            switch (row_source)
            {
              case RealtimeRowSource.EventDelete:
                //TODO - handle deletes
                break;
              case RealtimeRowSource.EventInsert:
                //TODO handle inserts
                break;
              case RealtimeRowSource.PreExisting:
                //TODO handle pre-existing rows
                break;
            }
          }
        }
      }
    }//row cursor is disposed. row cursor is unsubscribed
  }
});
Search And Subscribe With Cancellation
await QueuedTask.Run(async () =>
{
  //Recycling cursor - 2nd param "true"
  //or streamLayer.Subscribe(qfilter, true) to just subscribe
  using (var rc = streamLayer.SearchAndSubscribe(qfilter, true))
  {
    //auto-cancel after 20 seconds
    var cancel = new CancellationTokenSource(new TimeSpan(0, 0, 20));
    //catch TaskCanceledException
    try
    {
      while (await rc.WaitForRowsAsync(cancel.Token))
      {
        //check for row events
        while (rc.MoveNext())
        {
          using (var row = rc.Current)
          {
            //etc
          }
        }
      }
    }
    catch (TaskCanceledException )
    {
      //Handle cancellation as needed
    }
    cancel.Dispose();
  }
});
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also