public RealtimeRowSource GetRowSource()
Public Function GetRowSource() As RealtimeRowSource
Return Value
A value of RealtimeRowSource specifying the source of this real-time row.
public RealtimeRowSource GetRowSource()
Public Function GetRowSource() As RealtimeRowSource
Exception | Description |
---|---|
ArcGIS.Core.Data.Exceptions.GeodatabaseException | A geodatabase-related exception has occurred. |
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 } } } });
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 tce) { //Handle cancellation as needed } cancel.Dispose(); } });
//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 } });
//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 } });
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 tce) { //Handle cancellation as needed } cancel.Dispose(); } });
Target Platforms: Windows 11, Windows 10, Windows 8.1