void IEditTask.OnFinishSketch()
{
if (m_editSketch == null)
{
return;
}
bool HasCutPolygons = false;
//Change the cursor to be hourglass shape.
System.Windows.Forms.Cursor.Current = Cursors.WaitCursor;
try
{
//Get the geometry that performs the cut from the edit sketch.
IGeometry cutGeometry = m_editSketch.Geometry;
//The sketch geometry is simplified to deal with a multi-part sketch as well
//as the case where the sketch loops back over itself.
ITopologicalOperator2 topoOperator = cutGeometry as ITopologicalOperator2;
topoOperator.IsKnownSimple_2 = false;
topoOperator.Simplify();
//Get ready to invalidate the features.
IInvalidArea refreshArea = new InvalidAreaClass();
refreshArea.Add(cutGeometry.Envelope);
//Create the spatial filter to search for features in the target feature class.
//The spatial relationship we care about is whether the interior of the line
//intesects the interior of the polygon.
ISpatialFilter spatialFilter = new SpatialFilterClass();
spatialFilter.Geometry = m_editSketch.Geometry;
spatialFilter.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects;
//Find the polygon features that cross the sketch.
IFeatureClass featureClass = m_editLayer.CurrentLayer.FeatureClass;
IFeatureCursor featureCursor = featureClass.Search(spatialFilter, false);
//Only do work if there are features that intersect the edit sketch.
IFeature origFeature = featureCursor.NextFeature();
if (origFeature != null)
{
//Check the first feature to see if it is ZAware and if it needs to make the
//cut geometry ZAware.
IZAware zAware = origFeature.Shape as IZAware;
if (zAware.ZAware)
{
zAware = cutGeometry as IZAware;
zAware.ZAware = true;
}
//The result selection set will be the new features created. This means
//we need to add the currently selected features to the refresh area so
//they are correctly invalidated.
if (m_editor.SelectionCount > 0)
{
IEnumFeature selectedFeatures = m_editor.EditSelection;
selectedFeatures.Reset();
IFeature selectedFeature = selectedFeatures.Next();
while (selectedFeature != null)
{
refreshArea.Add(selectedFeature);
selectedFeature = selectedFeatures.Next();
}
}
//Initialize the selection set for the new features.
IFeatureSelection featureSelect = m_editLayer.CurrentLayer as IFeatureSelection;
featureSelect.Clear();
//Cache the new features created.
ISelectionSet selectionSet = featureSelect.SelectionSet;
//Start an edit operation so we can have undo/redo.
m_editor.StartOperation();
//Cycle through the features, cutting with the sketch.
while (origFeature != null)
{
try
{
//Add the feature to the invalidate object.
refreshArea.Add(origFeature);
//Split the feature. Use the IFeatureEdit::Split method which ensures
//the attributes are correctly dealt with.
IFeatureEdit featureEdit = origFeature as IFeatureEdit;
//Set to hold the new features that are created by the Split.
ISet newFeaturesSet = featureEdit.Split(cutGeometry);
//New features have been created, loop through the set and flash
//each feature and get it's OID for the final selection set.
if (newFeaturesSet != null)
{
newFeaturesSet.Reset();
//A list to hold the selected features' OIDs.
List <int> iOIDList = new List <int>();
for (int featureCount = 0; featureCount < newFeaturesSet.Count; featureCount++)
{
HasCutPolygons = true;
//Flash the new features.
IFeature newFeature = newFeaturesSet.Next() as IFeature;
FlashGeometry(newFeature.Shape, m_editor.Display);
//Add the feature to the new selection set
iOIDList.Add(newFeature.OID);
}
int[] iOIDArray = iOIDList.ToArray();
selectionSet.AddList(newFeaturesSet.Count, ref iOIDArray[0]);
}
}
catch (COMException)
{
}
finally
{
//Continue to work on the next feature if it fails to split the current one.
origFeature = featureCursor.NextFeature();
}
}
//If any polygons were cut, invalidate the display and stop the edit operation.
if (HasCutPolygons)
{
//Clear the map's selection.
m_mxDoc.FocusMap.ClearSelection();
//Select the new features.
featureSelect.SelectionSet = selectionSet;
//Refresh the display.
refreshArea.Display = m_editor.Display;
refreshArea.Invalidate((short)esriScreenCache.esriAllScreenCaches);
//Complete the edit operation.
m_editor.StopOperation("Cut Polygons Without Selection");
//As we changed the selection set, the map has no idea we did this.
//Fire the event to inform others the selection has changed.
featureSelect.SelectionChanged();
}
else
{
m_editor.AbortOperation();
}
}
}
catch (Exception e)
{
MessageBox.Show("Unable to perform the cut task.\n" + e.ToString());
//In the event of an error, abort the operation.
m_editor.AbortOperation();
}
finally
{
//Change the cursor shape to default.
System.Windows.Forms.Cursor.Current = Cursors.Default;
}
}