缩放的地理范围选功能。使用这种方法确保所有选中的功能是显示在屏幕上。
///<summary>Zooms to the geographic extent of the selected features. Using this method ensures that all the selected features are displayed on the screen.</summary>
///
///<param name="globe">An IGlobe interface</param>
///
///<remarks></remarks>
public void ZoomToSelectedGlobeFeatures(ESRI.ArcGIS.GlobeCore.IGlobe globe)
{
ESRI.ArcGIS.GlobeCore.IGlobeDisplay globeDisplay = globe.GlobeDisplay;
ESRI.ArcGIS.Analyst3D.ISceneViewer sceneViewer = globeDisplay.ActiveViewer;
ESRI.ArcGIS.Analyst3D.ICamera camera = sceneViewer.Camera;
ESRI.ArcGIS.GlobeCore.IGlobeCamera globeCamera = (ESRI.ArcGIS.GlobeCore.IGlobeCamera)camera; // Explicit Cast
ESRI.ArcGIS.Analyst3D.IScene scene = globeDisplay.Scene;
ESRI.ArcGIS.Carto.IEnumLayer enumLayer = scene.get_Layers(null, true);
ESRI.ArcGIS.Geometry.IEnvelope envelope = new ESRI.ArcGIS.Geometry.EnvelopeClass();
envelope.SetEmpty();
ESRI.ArcGIS.Geometry.IEnvelope layersExtentEnvelope = new ESRI.ArcGIS.Geometry.EnvelopeClass();
layersExtentEnvelope.SetEmpty();
ESRI.ArcGIS.Geometry.IZAware ZAware = (ESRI.ArcGIS.Geometry.IZAware)envelope; // Explicit Cast
ZAware.ZAware = (true);
ESRI.ArcGIS.Geodatabase.ISpatialFilter spatialFilter = new ESRI.ArcGIS.Geodatabase.SpatialFilterClass();
ESRI.ArcGIS.Geometry.ISpatialReference spatialReference = scene.SpatialReference;
System.Boolean haveFeatures = false;
enumLayer.Reset();
ESRI.ArcGIS.Carto.ILayer layer;
while ((layer = enumLayer.Next()) != null)
{
if (layer == null)
break;
if (layer is ESRI.ArcGIS.Carto.IFeatureLayer)
{
ESRI.ArcGIS.Carto.IFeatureLayer featureLayer = (ESRI.ArcGIS.Carto.IFeatureLayer)layer; // Explicit Cast
ESRI.ArcGIS.Carto.IFeatureSelection featureSelection = (ESRI.ArcGIS.Carto.IFeatureSelection)layer; // Explicit Cast
ESRI.ArcGIS.Geodatabase.ISelectionSet selectionSet = featureSelection.SelectionSet;
ESRI.ArcGIS.Geodatabase.IFeatureClass featureClass = featureLayer.FeatureClass;
System.String shapeField = featureClass.ShapeFieldName;
spatialFilter.GeometryField = shapeField;
spatialFilter.set_OutputSpatialReference(shapeField, spatialReference);
// The next 2 lines of code are different from many other ArcObjects programming techniques in that the
// ICursor Interface variable 'cursor' is initialized to a Null value. It is set by reference with the
// call to the Search method; hence the need for the 'out' argument (see MSDN for more information).
ESRI.ArcGIS.Geodatabase.ICursor cursor;
selectionSet.Search(spatialFilter, true, out cursor);
ESRI.ArcGIS.Geodatabase.IFeatureCursor featureCursor = (ESRI.ArcGIS.Geodatabase.IFeatureCursor)cursor; // Explicit Cast
System.Boolean getLayerExtent = true;
ESRI.ArcGIS.Geodatabase.IFeature feature; // Automatically initialized to null. Used to test existence of a feature in the featureCursor
while ((feature = featureCursor.NextFeature()) != null)
{
ESRI.ArcGIS.Geometry.IGeometry geometry = feature.Shape;
ESRI.ArcGIS.Geometry.IEnvelope featureExtent = geometry.Envelope;
envelope.Union(featureExtent);
haveFeatures = true;
if (getLayerExtent)
{
ESRI.ArcGIS.Geodatabase.IGeoDataset geoDataset = (ESRI.ArcGIS.Geodatabase.IGeoDataset)featureLayer; // Explicit Cast
if (geoDataset != null)
{
ESRI.ArcGIS.Geometry.IEnvelope layerExtent = geoDataset.Extent;
layersExtentEnvelope.Union(layerExtent);
}
getLayerExtent = false;
}
}
}
}
// Since the size of points is very small, we use a special case to zoom in closer
System.Double width = envelope.Width;
System.Double height = envelope.Height;
if (width == 0.0 && height == 0.0) // Must be a single point, Zoom to 1 x 1 degree area,
{ // or lets say 1/20th of layer extent, whichever is smallest.
System.Double dim = 1.0;
System.Boolean bEmpty = layersExtentEnvelope.IsEmpty;
if (!bEmpty)
{
System.Double layerWidth = layersExtentEnvelope.Width;
System.Double layerHeight = layersExtentEnvelope.Height;
System.Double layerDim = System.Math.Max(layerWidth, layerHeight) * 0.05;
if (layerDim > 0.0)
dim = System.Math.Min(1.0, layerDim);
}
System.Double xMin = envelope.XMin;
System.Double yMin = envelope.YMin;
ESRI.ArcGIS.Geometry.IPoint point = new ESRI.ArcGIS.Geometry.PointClass();
point.X = xMin;
point.Y = yMin;
envelope.Width = dim;
envelope.Height = dim;
envelope.CenterAt(point);
}
else if (width == 0.0 || height == 0.0)
{
System.Double maxDim = System.Math.Max(width, height);
envelope.Width = maxDim;
envelope.Height = maxDim;
}
globeCamera.SetToZoomToExtents(envelope, globe, sceneViewer);
sceneViewer.Redraw(true);