ESRI.ArcGIS.Mobile
GetNearestVertex(Point,Coordinate,Int32,Int32,Double) Method
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ESRI.ArcGIS.Mobile.Geometries Namespace > Geometry Class > GetNearestVertex Method : GetNearestVertex(Point,Coordinate,Int32,Int32,Double) Method

Visual Basic (Declaration)
C#

inputPoint: Input point to compare to.

nearestVertex: Returns the nearest vertex coordinate.

partIndex: Returns the part index of the nearest coordinate.

vertexIndex: Returns the vertex index in the part.

squareDistanceFound: Returns the square distance to the closest vertex.

Finds a vertex on the geometry which is the closet one to the input point location.

Syntax

Visual Basic (Declaration)
Public Overloads Sub GetNearestVertex( _ ByVal inputPoint As Point, _ ByVal nearestVertex As Coordinate, _ ByRef partIndex As Integer, _ ByRef vertexIndex As Integer, _ ByRef squareDistanceFound As Double _ )

Visual Basic (Declaration)

Public Overloads Sub GetNearestVertex( _
   ByVal inputPoint As Point, _
   ByVal nearestVertex As Coordinate, _
   ByRef partIndex As Integer, _
   ByRef vertexIndex As Integer, _
   ByRef squareDistanceFound As Double _
)

C#
public void GetNearestVertex( Point inputPoint, Coordinate nearestVertex, ref int partIndex, ref int vertexIndex, ref double squareDistanceFound )

Parameters

inputPoint: Input point to compare to.
nearestVertex: Returns the nearest vertex coordinate.
partIndex: Returns the part index of the nearest coordinate.
vertexIndex: Returns the vertex index in the part.
squareDistanceFound: Returns the square distance to the closest vertex.

Exceptions

Exception	Description
ArgumentNullException	Null point.

Example

C# Copy Code

C#	Copy Code
private Coordinate FindSnapCoordinate(ESRI.ArcGIS.Mobile.MapMouseEventArgs e) { System.Drawing.Rectangle rec = new Rectangle(e.X, e.Y, 100, 100); Envelope envelope = map1.ToMap(rec); QueryFilter queryFilter = new QueryFilter(envelope, esriGeometricRelationship.Intersect); MapLayerCollection mapLayerCollection = map1.MapLayers; MapLayer mapLayer = mapLayerCollection["Tax Parcels"]; FeatureLayer featLayer = mapLayer.Layer as FeatureLayer; FeatureDataReader dataReader = featLayer.GetDataReader(queryFilter); double dist = 0; double minDist = double.MaxValue; Coordinate nearest = null; while (dataReader.Read()) { Geometry geometry = dataReader.GetGeometry(); Coordinate c = geometry.GetNearestVertex(e.MapCoordinate, ref dist); if (dist < minDist) { minDist = dist; nearest = c; } } return nearest; }

private Coordinate FindSnapCoordinate(ESRI.ArcGIS.Mobile.MapMouseEventArgs e) 
{ 
System.Drawing.Rectangle rec = new Rectangle(e.X, e.Y, 100, 100); 
Envelope envelope = map1.ToMap(rec); 
 
QueryFilter queryFilter = new QueryFilter(envelope, esriGeometricRelationship.Intersect); 
MapLayerCollection mapLayerCollection = map1.MapLayers; 
MapLayer mapLayer = mapLayerCollection["Tax Parcels"]; 
FeatureLayer featLayer = mapLayer.Layer as FeatureLayer; 
 
FeatureDataReader dataReader = featLayer.GetDataReader(queryFilter); 
 
double dist = 0; 
double minDist = double.MaxValue; 
Coordinate nearest = null; 
 
while (dataReader.Read()) 
{ 
    Geometry geometry = dataReader.GetGeometry(); 
   Coordinate c = geometry.GetNearestVertex(e.MapCoordinate, ref dist); 
   if (dist < minDist) 
   { 
     minDist = dist; 
     nearest = c; 
  } 
 } 
return nearest; 
}

Remarks

You can use GetNearestVertex to determine which coordinate on the geometry is closest to a particular point location. For example, you might be interested in determining how close the current mouse location is to a particular geometry, and further what coordinate on that geometry is the closest. You must supply a reference for a returned distance. This distance will be in map units. Use the return distance to determine if the return coordinate is the closet coordinate to the mouse location.

Requirements

Target Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, Windows Vista, Windows Server 2008 family